dm: add integrity target

The dm-integrity target emulates a block device that has additional
per-sector tags that can be used for storing integrity information.

A general problem with storing integrity tags with every sector is that
writing the sector and the integrity tag must be atomic - i.e. in case of
crash, either both sector and integrity tag or none of them is written.

To guarantee write atomicity the dm-integrity target uses a journal. It
writes sector data and integrity tags into a journal, commits the journal
and then copies the data and integrity tags to their respective location.

The dm-integrity target can be used with the dm-crypt target - in this
situation the dm-crypt target creates the integrity data and passes them
to the dm-integrity target via bio_integrity_payload attached to the bio.
In this mode, the dm-crypt and dm-integrity targets provide authenticated
disk encryption - if the attacker modifies the encrypted device, an I/O
error is returned instead of random data.

The dm-integrity target can also be used as a standalone target, in this
mode it calculates and verifies the integrity tag internally. In this
mode, the dm-integrity target can be used to detect silent data
corruption on the disk or in the I/O path.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Documentation/device-mapper/dm-integrity.txt

+The dm-integrity target emulates a block device that has additional
+per-sector tags that can be used for storing integrity information.
+
+A general problem with storing integrity tags with every sector is that
+writing the sector and the integrity tag must be atomic - i.e. in case of
+crash, either both sector and integrity tag or none of them is written.
+
+To guarantee write atomicity, the dm-integrity target uses journal, it
+writes sector data and integrity tags into a journal, commits the journal
+and then copies the data and integrity tags to their respective location.
+
+The dm-integrity target can be used with the dm-crypt target - in this
+situation the dm-crypt target creates the integrity data and passes them
+to the dm-integrity target via bio_integrity_payload attached to the bio.
+In this mode, the dm-crypt and dm-integrity targets provide authenticated
+disk encryption - if the attacker modifies the encrypted device, an I/O
+error is returned instead of random data.
+
+The dm-integrity target can also be used as a standalone target, in this
+mode it calculates and verifies the integrity tag internally. In this
+mode, the dm-integrity target can be used to detect silent data
+corruption on the disk or in the I/O path.
+
+
+When loading the target for the first time, the kernel driver will format
+the device. But it will only format the device if the superblock contains
+zeroes. If the superblock is neither valid nor zeroed, the dm-integrity
+target can't be loaded.
+
+To use the target for the first time:
+1. overwrite the superblock with zeroes
+2. load the dm-integrity target with one-sector size, the kernel driver
+	will format the device
+3. unload the dm-integrity target
+4. read the "provided_data_sectors" value from the superblock
+5. load the dm-integrity target with the the target size
+	"provided_data_sectors"
+6. if you want to use dm-integrity with dm-crypt, load the dm-crypt target
+	with the size "provided_data_sectors"
+
+
+Target arguments:
+
+1. the underlying block device
+
+2. the number of reserved sector at the beginning of the device - the
+	dm-integrity won't read of write these sectors
+
+3. the size of the integrity tag (if "-" is used, the size is taken from
+	the internal-hash algorithm)
+
+4. mode:
+	D - direct writes (without journal) - in this mode, journaling is
+		not used and data sectors and integrity tags are written
+		separately. In case of crash, it is possible that the data
+		and integrity tag doesn't match.
+	J - journaled writes - data and integrity tags are written to the
+		journal and atomicity is guaranteed. In case of crash,
+		either both data and tag or none of them are written. The
+		journaled mode degrades write throughput twice because the
+		data have to be written twice.
+
+5. the number of additional arguments
+
+Additional arguments:
+
+journal-sectors:number
+	The size of journal, this argument is used only if formatting the
+	device. If the device is already formatted, the value from the
+	superblock is used.
+
+interleave-sectors:number
+	The number of interleaved sectors. This values is rounded down to
+	a power of two. If the device is already formatted, the value from
+	the superblock is used.
+
+buffer-sectors:number
+	The number of sectors in one buffer. The value is rounded down to
+	a power of two.
+
+	The tag area is accessed using buffers, the buffer size is
+	configurable. The large buffer size means that the I/O size will
+	be larger, but there could be less I/Os issued.
+
+journal-watermark:number
+	The journal watermark in percents. When the size of the journal
+	exceeds this watermark, the thread that flushes the journal will
+	be started.
+
+commit-time:number
+	Commit time in milliseconds. When this time passes, the journal is
+	written. The journal is also written immediatelly if the FLUSH
+	request is received.
+
+internal-hash:algorithm(:key)	(the key is optional)
+	Use internal hash or crc.
+	When this argument is used, the dm-integrity target won't accept
+	integrity tags from the upper target, but it will automatically
+	generate and verify the integrity tags.
+
+	You can use a crc algorithm (such as crc32), then integrity target
+	will protect the data against accidental corruption.
+	You can also use a hmac algorithm (for example
+	"hmac(sha256):0123456789abcdef"), in this mode it will provide
+	cryptographic authentication of the data without encryption.
+
+	When this argument is not used, the integrity tags are accepted
+	from an upper layer target, such as dm-crypt. The upper layer
+	target should check the validity of the integrity tags.
+
+journal-crypt:algorithm(:key)	(the key is optional)
+	Encrypt the journal using given algorithm to make sure that the
+	attacker can't read the journal. You can use a block cipher here
+	(such as "cbc(aes)") or a stream cipher (for example "chacha20",
+	"salsa20", "ctr(aes)" or "ecb(arc4)").
+
+	The journal contains history of last writes to the block device,
+	an attacker reading the journal could see the last sector nubmers
+	that were written. From the sector numbers, the attacker can infer
+	the size of files that were written. To protect against this
+	situation, you can encrypt the journal.
+
+journal-mac:algorithm(:key)	(the key is optional)
+	Protect sector numbers in the journal from accidental or malicious
+	modification. To protect against accidental modification, use a
+	crc algorithm, to protect against malicious modification, use a
+	hmac algorithm with a key.
+
+	This option is not needed when using internal-hash because in this
+	mode, the integrity of journal entries is checked when replaying
+	the journal. Thus, modified sector number would be detected at
+	this stage.
+
+
+The journal mode (D/J), buffer-sectors, journal-watermark, commit-time can
+be changed when reloading the target (load an inactive table and swap the
+tables with suspend and resume). The other arguments should not be changed
+when reloading the target because the layout of disk data depend on them
+and the reloaded target would be non-functional.
+
+
+The layout of the formatted block device:
+* reserved sectors (they are not used by this target, they can be used for
+  storing LUKS metadata or for other purpose), the size of the reserved
+  area is specified in the target arguments
+* superblock (4kiB)
+	* magic string - identifies that the device was formatted
+	* version
+	* log2(interleave sectors)
+	* integrity tag size
+	* the number of journal sections
+	* provided data sectors - the number of sectors that this target
+	  provides (i.e. the size of the device minus the size of all
+	  metadata and padding). The user of this target should not send
+	  bios that access data beyond the "provided data sectors" limit.
+	* flags - a flag is set if journal-mac is used
+* journal
+	The journal is divided into sections, each section contains:
+	* metadata area (4kiB), it contains journal entries
+	  every journal entry contains:
+		* logical sector (specifies where the data and tag should
+		  be written)
+		* last 8 bytes of data
+		* integrity tag (the size is specified in the superblock)
+	    every metadata sector ends with
+		* mac (8-bytes), all the macs in 8 metadata sectors form a
+		  64-byte value. It is used to store hmac of sector
+		  numbers in the journal section, to protect against a
+		  possibility that the attacker tampers with sector
+		  numbers in the journal.
+		* commit id
+	* data area (the size is variable; it depends on how many journal
+	  entries fit into the metadata area)
+	    every sector in the data area contains:
+		* data (504 bytes of data, the last 8 bytes are stored in
+		  the journal entry)
+		* commit id
+	To test if the whole journal section was written correctly, every
+	512-byte sector of the journal ends with 8-byte commit id. If the
+	commit id matches on all sectors in a journal section, then it is
+	assumed that the section was written correctly. If the commit id
+	doesn't match, the section was written partially and it should not
+	be replayed.
+* one or more runs of interleaved tags and data. Each run contains:
+	* tag area - it contains integrity tags. There is one tag for each
+	  sector in the data area
+	* data area - it contains data sectors. The number of data sectors
+	  in one run must be a power of two. log2 of this value is stored
+	  in the superblock.

drivers/md/Kconfig

@@ -500,4 +500,14 @@ config DM_LOG_WRITES
 
 	  If unsure, say N.
 
+config DM_INTEGRITY
+	tristate "Integrity target"
+	depends on BLK_DEV_DM
+	select BLK_DEV_INTEGRITY
+	select DM_BUFIO
+	select CRYPTO
+	select ASYNC_XOR
+	---help---
+	   This is the integrity target.
+
 endif # MD

drivers/md/Makefile

@@ -59,6 +59,7 @@ obj-$(CONFIG_DM_CACHE)		+= dm-cache.o
 obj-$(CONFIG_DM_CACHE_SMQ)	+= dm-cache-smq.o
 obj-$(CONFIG_DM_ERA)		+= dm-era.o
 obj-$(CONFIG_DM_LOG_WRITES)	+= dm-log-writes.o
+obj-$(CONFIG_DM_INTEGRITY)	+= dm-integrity.o
 
 ifeq ($(CONFIG_DM_UEVENT),y)
 dm-mod-objs			+= dm-uevent.o

drivers/md/dm-integrity.c

+/*
+ * Copyright (C) 2016-2017 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2016-2017 Milan Broz
+ * Copyright (C) 2016-2017 Mikulas Patocka
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/module.h>
+#include <linux/device-mapper.h>
+#include <linux/dm-io.h>
+#include <linux/vmalloc.h>
+#include <linux/sort.h>
+#include <linux/rbtree.h>
+#include <linux/delay.h>
+#include <linux/random.h>
+#include <crypto/hash.h>
+#include <crypto/skcipher.h>
+#include <linux/async_tx.h>
+#include "dm-bufio.h"
+
+#define DM_MSG_PREFIX "integrity"
+
+#define DEFAULT_INTERLEAVE_SECTORS	32768
+#define DEFAULT_JOURNAL_SIZE_FACTOR	7
+#define DEFAULT_BUFFER_SECTORS		128
+#define DEFAULT_JOURNAL_WATERMARK	50
+#define DEFAULT_SYNC_MSEC		10000
+#define DEFAULT_MAX_JOURNAL_SECTORS	131072
+#define MIN_INTERLEAVE_SECTORS		3
+#define MAX_INTERLEAVE_SECTORS		31
+#define METADATA_WORKQUEUE_MAX_ACTIVE	16
+
+/*
+ * Warning - DEBUG_PRINT prints security-sensitive data to the log,
+ * so it should not be enabled in the official kernel
+ */
+//#define DEBUG_PRINT
+//#define INTERNAL_VERIFY
+
+/*
+ * On disk structures
+ */
+
+#define SB_MAGIC			"integrt"
+#define SB_VERSION			1
+#define SB_SECTORS			8
+
+struct superblock {
+	__u8 magic[8];
+	__u8 version;
+	__u8 log2_interleave_sectors;
+	__u16 integrity_tag_size;
+	__u32 journal_sections;
+	__u64 provided_data_sectors;	/* userspace uses this value */
+	__u32 flags;
+};
+
+#define SB_FLAG_HAVE_JOURNAL_MAC	0x1
+
+#define	JOURNAL_ENTRY_ROUNDUP		8
+
+typedef __u64 commit_id_t;
+#define JOURNAL_MAC_PER_SECTOR		8
+
+struct journal_entry {
+	union {
+		struct {
+			__u32 sector_lo;
+			__u32 sector_hi;
+		} s;
+		__u64 sector;
+	} u;
+	commit_id_t last_bytes;
+	__u8 tag[0];
+};
+
+#if BITS_PER_LONG == 64
+#define journal_entry_set_sector(je, x)		do { smp_wmb(); ACCESS_ONCE((je)->u.sector) = cpu_to_le64(x); } while (0)
+#define journal_entry_get_sector(je)		le64_to_cpu((je)->u.sector)
+#elif defined(CONFIG_LBDAF)
+#define journal_entry_set_sector(je, x)		do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); ACCESS_ONCE((je)->u.s.sector_hi) = cpu_to_le32((x) >> 32); } while (0)
+#define journal_entry_get_sector(je)		le64_to_cpu((je)->u.sector)
+#else
+#define journal_entry_set_sector(je, x)		do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); ACCESS_ONCE((je)->u.s.sector_hi) = cpu_to_le32(0); } while (0)
+#define journal_entry_get_sector(je)		le32_to_cpu((je)->u.s.sector_lo)
+#endif
+#define journal_entry_is_unused(je)		((je)->u.s.sector_hi == cpu_to_le32(-1))
+#define journal_entry_set_unused(je)		do { ((je)->u.s.sector_hi = cpu_to_le32(-1)); } while (0)
+#define journal_entry_is_inprogress(je)		((je)->u.s.sector_hi == cpu_to_le32(-2))
+#define journal_entry_set_inprogress(je)	do { ((je)->u.s.sector_hi = cpu_to_le32(-2)); } while (0)
+
+#define JOURNAL_BLOCK_SECTORS		8
+#define JOURNAL_SECTOR_DATA		((1 << SECTOR_SHIFT) - sizeof(commit_id_t))
+#define JOURNAL_MAC_SIZE		(JOURNAL_MAC_PER_SECTOR * JOURNAL_BLOCK_SECTORS)
+
+struct journal_sector {
+	__u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
+	__u8 mac[JOURNAL_MAC_PER_SECTOR];
+	commit_id_t commit_id;
+};
+
+#define MAX_TAG_SIZE			(JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR - offsetof(struct journal_entry, tag))
+
+#define METADATA_PADDING_SECTORS	8
+
+#define N_COMMIT_IDS			4
+
+static unsigned char prev_commit_seq(unsigned char seq)
+{
+	return (seq + N_COMMIT_IDS - 1) % N_COMMIT_IDS;
+}
+
+static unsigned char next_commit_seq(unsigned char seq)
+{
+	return (seq + 1) % N_COMMIT_IDS;
+}
+
+/*
+ * In-memory structures
+ */
+
+struct journal_node {
+	struct rb_node node;
+	sector_t sector;
+};
+
+struct alg_spec {
+	char *alg_string;
+	char *key_string;
+	__u8 *key;
+	unsigned key_size;
+};
+
+struct dm_integrity_c {
+	struct dm_dev *dev;
+	unsigned tag_size;
+	__s8 log2_tag_size;
+	sector_t start;
+	mempool_t *journal_io_mempool;
+	struct dm_io_client *io;
+	struct dm_bufio_client *bufio;
+	struct workqueue_struct *metadata_wq;
+	struct superblock *sb;
+	unsigned journal_pages;
+	struct page_list *journal;
+	struct page_list *journal_io;
+	struct page_list *journal_xor;
+
+	struct crypto_skcipher *journal_crypt;
+	struct scatterlist **journal_scatterlist;
+	struct scatterlist **journal_io_scatterlist;
+	struct skcipher_request **sk_requests;
+
+	struct crypto_shash *journal_mac;
+
+	struct journal_node *journal_tree;
+	struct rb_root journal_tree_root;
+
+	sector_t provided_data_sectors;
+
+	unsigned short journal_entry_size;
+	unsigned char journal_entries_per_sector;
+	unsigned char journal_section_entries;
+	unsigned char journal_section_sectors;
+	unsigned journal_sections;
+	unsigned journal_entries;
+	sector_t device_sectors;
+	unsigned initial_sectors;
+	unsigned metadata_run;
+	__s8 log2_metadata_run;
+	__u8 log2_buffer_sectors;
+
+	unsigned char mode;
+	bool suspending;
+
+	int failed;
+
+	struct crypto_shash *internal_hash;
+
+	/* these variables are locked with endio_wait.lock */
+	struct rb_root in_progress;
+	wait_queue_head_t endio_wait;
+	struct workqueue_struct *wait_wq;
+
+	unsigned char commit_seq;
+	commit_id_t commit_ids[N_COMMIT_IDS];
+
+	unsigned committed_section;
+	unsigned n_committed_sections;
+
+	unsigned uncommitted_section;
+	unsigned n_uncommitted_sections;
+
+	unsigned free_section;
+	unsigned char free_section_entry;
+	unsigned free_sectors;
+
+	unsigned free_sectors_threshold;
+
+	struct workqueue_struct *commit_wq;
+	struct work_struct commit_work;
+
+	struct workqueue_struct *writer_wq;
+	struct work_struct writer_work;
+
+	struct bio_list flush_bio_list;
+
+	unsigned long autocommit_jiffies;
+	struct timer_list autocommit_timer;
+	unsigned autocommit_msec;
+
+	wait_queue_head_t copy_to_journal_wait;
+
+	struct completion crypto_backoff;
+
+	bool journal_uptodate;
+	bool just_formatted;
+
+	struct alg_spec internal_hash_alg;
+	struct alg_spec journal_crypt_alg;
+	struct alg_spec journal_mac_alg;
+};
+
+struct dm_integrity_range {
+	sector_t logical_sector;
+	unsigned n_sectors;
+	struct rb_node node;
+};
+
+struct dm_integrity_io {
+	struct work_struct work;
+
+	struct dm_integrity_c *ic;
+	bool write;
+	bool fua;
+
+	struct dm_integrity_range range;
+
+	sector_t metadata_block;
+	unsigned metadata_offset;
+
+	atomic_t in_flight;
+	int bi_error;
+
+	struct completion *completion;
+
+	struct block_device *orig_bi_bdev;
+	bio_end_io_t *orig_bi_end_io;
+	struct bio_integrity_payload *orig_bi_integrity;
+	struct bvec_iter orig_bi_iter;
+};
+
+struct journal_completion {
+	struct dm_integrity_c *ic;
+	atomic_t in_flight;
+	struct completion comp;
+};
+
+struct journal_io {
+	struct dm_integrity_range range;
+	struct journal_completion *comp;
+};
+
+static struct kmem_cache *journal_io_cache;
+
+#define JOURNAL_IO_MEMPOOL	32
+
+#ifdef DEBUG_PRINT
+#define DEBUG_print(x, ...)	printk(KERN_DEBUG x, ##__VA_ARGS__)
+static void __DEBUG_bytes(__u8 *bytes, size_t len, const char *msg, ...)
+{
+	va_list args;
+	va_start(args, msg);
+	vprintk(msg, args);
+	va_end(args);
+	if (len)
+		pr_cont(":");
+	while (len) {
+		pr_cont(" %02x", *bytes);
+		bytes++;
+		len--;
+	}
+	pr_cont("\n");
+}
+#define DEBUG_bytes(bytes, len, msg, ...)	__DEBUG_bytes(bytes, len, KERN_DEBUG msg, ##__VA_ARGS__)
+#else
+#define DEBUG_print(x, ...)			do { } while (0)
+#define DEBUG_bytes(bytes, len, msg, ...)	do { } while (0)
+#endif
+
+/*
+ * DM Integrity profile, protection is performed layer above (dm-crypt)
+ */
+static struct blk_integrity_profile dm_integrity_profile = {
+	.name			= "DM-DIF-EXT-TAG",
+	.generate_fn		= NULL,
+	.verify_fn		= NULL,
+};
+
+static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map);
+static void integrity_bio_wait(struct work_struct *w);
+static void dm_integrity_dtr(struct dm_target *ti);
+
+static void dm_integrity_io_error(struct dm_integrity_c *ic, const char *msg, int err)
+{
+	if (!cmpxchg(&ic->failed, 0, err))
+		DMERR("Error on %s: %d", msg, err);
+}
+
+static int dm_integrity_failed(struct dm_integrity_c *ic)
+{
+	return ACCESS_ONCE(ic->failed);
+}
+
+static commit_id_t dm_integrity_commit_id(struct dm_integrity_c *ic, unsigned i,
+					  unsigned j, unsigned char seq)
+{
+	/*
+	 * Xor the number with section and sector, so that if a piece of
+	 * journal is written at wrong place, it is detected.
+	 */
+	return ic->commit_ids[seq] ^ cpu_to_le64(((__u64)i << 32) ^ j);
+}
+
+static void get_area_and_offset(struct dm_integrity_c *ic, sector_t data_sector,
+				sector_t *area, sector_t *offset)
+{
+	__u8 log2_interleave_sectors = ic->sb->log2_interleave_sectors;
+
+	*area = data_sector >> log2_interleave_sectors;
+	*offset = (unsigned)data_sector & ((1U << log2_interleave_sectors) - 1);
+}
+
+static __u64 get_metadata_sector_and_offset(struct dm_integrity_c *ic, sector_t area,
+					    sector_t offset, unsigned *metadata_offset)
+{
+	__u64 ms;
+	unsigned mo;
+
+	ms = area << ic->sb->log2_interleave_sectors;
+	if (likely(ic->log2_metadata_run >= 0))
+		ms += area << ic->log2_metadata_run;
+	else
+		ms += area * ic->metadata_run;
+	ms >>= ic->log2_buffer_sectors;
+
+	if (likely(ic->log2_tag_size >= 0)) {
+		ms += offset >> (SECTOR_SHIFT + ic->log2_buffer_sectors - ic->log2_tag_size);
+		mo = (offset << ic->log2_tag_size) & ((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - 1);
+	} else {
+		ms += (__u64)offset * ic->tag_size >> (SECTOR_SHIFT + ic->log2_buffer_sectors);
+		mo = (offset * ic->tag_size) & ((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - 1);
+	}
+	*metadata_offset = mo;
+	return ms;
+}
+
+static sector_t get_data_sector(struct dm_integrity_c *ic, sector_t area, sector_t offset)
+{
+	sector_t result;
+
+	result = area << ic->sb->log2_interleave_sectors;
+	if (likely(ic->log2_metadata_run >= 0))
+		result += (area + 1) << ic->log2_metadata_run;
+	else
+		result += (area + 1) * ic->metadata_run;
+
+	result += (sector_t)ic->initial_sectors + offset;
+	return result;
+}
+
+static void wraparound_section(struct dm_integrity_c *ic, unsigned *sec_ptr)
+{
+	if (unlikely(*sec_ptr >= ic->journal_sections))
+		*sec_ptr -= ic->journal_sections;
+}
+
+static int sync_rw_sb(struct dm_integrity_c *ic, int op, int op_flags)
+{
+	struct dm_io_request io_req;
+	struct dm_io_region io_loc;
+
+	io_req.bi_op = op;
+	io_req.bi_op_flags = op_flags;
+	io_req.mem.type = DM_IO_KMEM;
+	io_req.mem.ptr.addr = ic->sb;
+	io_req.notify.fn = NULL;
+	io_req.client = ic->io;
+	io_loc.bdev = ic->dev->bdev;
+	io_loc.sector = ic->start;
+	io_loc.count = SB_SECTORS;
+
+	return dm_io(&io_req, 1, &io_loc, NULL);
+}
+
+static void access_journal_check(struct dm_integrity_c *ic, unsigned section, unsigned offset,
+				 bool e, const char *function)
+{
+#if defined(CONFIG_DM_DEBUG) || defined(INTERNAL_VERIFY)
+	unsigned limit = e ? ic->journal_section_entries : ic->journal_section_sectors;
+
+	if (unlikely(section >= ic->journal_sections) ||
+	    unlikely(offset >= limit)) {
+		printk(KERN_CRIT "%s: invalid access at (%u,%u), limit (%u,%u)\n",
+			function, section, offset, ic->journal_sections, limit);
+		BUG();
+	}
+#endif
+}
+
+static void page_list_location(struct dm_integrity_c *ic, unsigned section, unsigned offset,
+			       unsigned *pl_index, unsigned *pl_offset)
+{
+	unsigned sector;
+
+	access_journal_check(ic, section, offset, false, "access_journal");
+
+	sector = section * ic->journal_section_sectors + offset;
+
+	*pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
+	*pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
+}
+
+static struct journal_sector *access_page_list(struct dm_integrity_c *ic, struct page_list *pl,
+					       unsigned section, unsigned offset, unsigned *n_sectors)
+{
+	unsigned pl_index, pl_offset;
+	char *va;
+
+	page_list_location(ic, section, offset, &pl_index, &pl_offset);
+
+	if (n_sectors)
+		*n_sectors = (PAGE_SIZE - pl_offset) >> SECTOR_SHIFT;
+
+	va = lowmem_page_address(pl[pl_index].page);
+
+	return (struct journal_sector *)(va + pl_offset);
+}
+
+static struct journal_sector *access_journal(struct dm_integrity_c *ic, unsigned section, unsigned offset)
+{
+	return access_page_list(ic, ic->journal, section, offset, NULL);
+}
+
+static struct journal_entry *access_journal_entry(struct dm_integrity_c *ic, unsigned section, unsigned n)
+{
+	unsigned rel_sector, offset;
+	struct journal_sector *js;
+
+	access_journal_check(ic, section, n, true, "access_journal_entry");
+
+	rel_sector = n % JOURNAL_BLOCK_SECTORS;
+	offset = n / JOURNAL_BLOCK_SECTORS;
+
+	js = access_journal(ic, section, rel_sector);
+	return (struct journal_entry *)((char *)js + offset * ic->journal_entry_size);
+}
+
+static struct journal_sector *access_journal_data(struct dm_integrity_c *ic, unsigned section, unsigned n)
+{
+	access_journal_check(ic, section, n, true, "access_journal_data");
+
+	return access_journal(ic, section, n + JOURNAL_BLOCK_SECTORS);
+}
+
+static void section_mac(struct dm_integrity_c *ic, unsigned section, __u8 result[JOURNAL_MAC_SIZE])
+{
+	SHASH_DESC_ON_STACK(desc, ic->journal_mac);
+	int r;
+	unsigned j, size;
+
+	desc->tfm = ic->journal_mac;
+	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	r = crypto_shash_init(desc);
+	if (unlikely(r)) {
+		dm_integrity_io_error(ic, "crypto_shash_init", r);
+		goto err;
+	}
+
+	for (j = 0; j < ic->journal_section_entries; j++) {
+		struct journal_entry *je = access_journal_entry(ic, section, j);
+		r = crypto_shash_update(desc, (__u8 *)&je->u.sector, sizeof je->u.sector);
+		if (unlikely(r)) {
+			dm_integrity_io_error(ic, "crypto_shash_update", r);
+			goto err;
+		}
+	}
+
+	size = crypto_shash_digestsize(ic->journal_mac);
+
+	if (likely(size <= JOURNAL_MAC_SIZE)) {
+		r = crypto_shash_final(desc, result);
+		if (unlikely(r)) {
+			dm_integrity_io_error(ic, "crypto_shash_final", r);
+			goto err;
+		}
+		memset(result + size, 0, JOURNAL_MAC_SIZE - size);
+	} else {
+		__u8 digest[size];
+		r = crypto_shash_final(desc, digest);
+		if (unlikely(r)) {
+			dm_integrity_io_error(ic, "crypto_shash_final", r);
+			goto err;
+		}
+		memcpy(result, digest, JOURNAL_MAC_SIZE);
+	}
+
+	return;
+err:
+	memset(result, 0, JOURNAL_MAC_SIZE);
+}
+
+static void rw_section_mac(struct dm_integrity_c *ic, unsigned section, bool wr)
+{
+	__u8 result[JOURNAL_MAC_SIZE];
+	unsigned j;
+
+	if (!ic->journal_mac)
+		return;
+
+	section_mac(ic, section, result);
+
+	for (j = 0; j < JOURNAL_BLOCK_SECTORS; j++) {
+		struct journal_sector *js = access_journal(ic, section, j);
+
+		if (likely(wr))
+			memcpy(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR);
+		else {
+			if (memcmp(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR))
+				dm_integrity_io_error(ic, "journal mac", -EILSEQ);
+		}
+	}
+}
+
+static void complete_journal_op(void *context)
+{
+	struct journal_completion *comp = context;
+	BUG_ON(!atomic_read(&comp->in_flight));
+	if (likely(atomic_dec_and_test(&comp->in_flight)))
+		complete(&comp->comp);
+}
+
+static void xor_journal(struct dm_integrity_c *ic, bool encrypt, unsigned section,
+			unsigned n_sections, struct journal_completion *comp)
+{
+	struct async_submit_ctl submit;
+	size_t n_bytes = (size_t)(n_sections * ic->journal_section_sectors) << SECTOR_SHIFT;
+	unsigned pl_index, pl_offset, section_index;
+	struct page_list *source_pl, *target_pl;
+
+	if (likely(encrypt)) {
+		source_pl = ic->journal;
+		target_pl = ic->journal_io;
+	} else {
+		source_pl = ic->journal_io;
+		target_pl = ic->journal;
+	}
+
+	page_list_location(ic, section, 0, &pl_index, &pl_offset);
+
+	atomic_add(roundup(pl_offset + n_bytes, PAGE_SIZE) >> PAGE_SHIFT, &comp->in_flight);
+
+	init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL, complete_journal_op, comp, NULL);
+
+	section_index = pl_index;
+
+	do {
+		size_t this_step;
+		struct page *src_pages[2];
+		struct page *dst_page;
+
+		while (unlikely(pl_index == section_index)) {
+			unsigned dummy;
+			if (likely(encrypt))
+				rw_section_mac(ic, section, true);
+			section++;
+			n_sections--;
+			if (!n_sections)
+				break;
+			page_list_location(ic, section, 0, &section_index, &dummy);
+		}
+
+		this_step = min(n_bytes, (size_t)PAGE_SIZE - pl_offset);
+		dst_page = target_pl[pl_index].page;
+		src_pages[0] = source_pl[pl_index].page;
+		src_pages[1] = ic->journal_xor[pl_index].page;
+
+		async_xor(dst_page, src_pages, pl_offset, 2, this_step, &submit);
+
+		pl_index++;
+		pl_offset = 0;
+		n_bytes -= this_step;
+	} while (n_bytes);
+
+	BUG_ON(n_sections);
+
+	async_tx_issue_pending_all();
+}
+
+static void complete_journal_encrypt(struct crypto_async_request *req, int err)
+{
+	struct journal_completion *comp = req->data;
+	if (unlikely(err)) {
+		if (likely(err == -EINPROGRESS)) {
+			complete(&comp->ic->crypto_backoff);
+			return;
+		}
+		dm_integrity_io_error(comp->ic, "asynchronous encrypt", err);
+	}
+	complete_journal_op(comp);
+}
+
+static bool do_crypt(bool encrypt, struct skcipher_request *req, struct journal_completion *comp)
+{
+	int r;
+	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
+				      complete_journal_encrypt, comp);
+	if (likely(encrypt))
+		r = crypto_skcipher_encrypt(req);
+	else
+		r = crypto_skcipher_decrypt(req);
+	if (likely(!r))
+		return false;
+	if (likely(r == -EINPROGRESS))
+		return true;
+	if (likely(r == -EBUSY)) {
+		wait_for_completion(&comp->ic->crypto_backoff);
+		reinit_completion(&comp->ic->crypto_backoff);
+		return true;
+	}
+	dm_integrity_io_error(comp->ic, "encrypt", r);
+	return false;
+}
+
+static void crypt_journal(struct dm_integrity_c *ic, bool encrypt, unsigned section,
+			  unsigned n_sections, struct journal_completion *comp)
+{
+	struct scatterlist **source_sg;
+	struct scatterlist **target_sg;
+
+	atomic_add(2, &comp->in_flight);
+
+	if (likely(encrypt)) {
+		source_sg = ic->journal_scatterlist;
+		target_sg = ic->journal_io_scatterlist;
+	} else {
+		source_sg = ic->journal_io_scatterlist;
+		target_sg = ic->journal_scatterlist;
+	}
+
+	do {
+		struct skcipher_request *req;
+		unsigned ivsize;
+		char *iv;
+
+		if (likely(encrypt))
+			rw_section_mac(ic, section, true);
+
+		req = ic->sk_requests[section];
+		ivsize = crypto_skcipher_ivsize(ic->journal_crypt);
+		iv = req->iv;
+
+		memcpy(iv, iv + ivsize, ivsize);
+
+		req->src = source_sg[section];
+		req->dst = target_sg[section];
+
+		if (unlikely(do_crypt(encrypt, req, comp)))
+			atomic_inc(&comp->in_flight);
+
+		section++;
+		n_sections--;
+	} while (n_sections);
+
+	atomic_dec(&comp->in_flight);
+	complete_journal_op(comp);
+}
+
+static void encrypt_journal(struct dm_integrity_c *ic, bool encrypt, unsigned section,
+			    unsigned n_sections, struct journal_completion *comp)
+{
+	if (ic->journal_xor)
+		return xor_journal(ic, encrypt, section, n_sections, comp);
+	else
+		return crypt_journal(ic, encrypt, section, n_sections, comp);
+}
+
+static void complete_journal_io(unsigned long error, void *context)
+{
+	struct journal_completion *comp = context;
+	if (unlikely(error != 0))
+		dm_integrity_io_error(comp->ic, "writing journal", -EIO);
+	complete_journal_op(comp);
+}
+
+static void rw_journal(struct dm_integrity_c *ic, int op, int op_flags, unsigned section,
+		       unsigned n_sections, struct journal_completion *comp)
+{
+	struct dm_io_request io_req;
+	struct dm_io_region io_loc;
+	unsigned sector, n_sectors, pl_index, pl_offset;
+	int r;
+
+	if (unlikely(dm_integrity_failed(ic))) {
+		if (comp)
+			complete_journal_io(-1UL, comp);
+		return;
+	}
+
+	sector = section * ic->journal_section_sectors;
+	n_sectors = n_sections * ic->journal_section_sectors;
+
+	pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
+	pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
+
+	io_req.bi_op = op;
+	io_req.bi_op_flags = op_flags;
+	io_req.mem.type = DM_IO_PAGE_LIST;
+	if (ic->journal_io)
+		io_req.mem.ptr.pl = &ic->journal_io[pl_index];
+	else
+		io_req.mem.ptr.pl = &ic->journal[pl_index];
+	io_req.mem.offset = pl_offset;
+	if (likely(comp != NULL)) {
+		io_req.notify.fn = complete_journal_io;
+		io_req.notify.context = comp;
+	} else {
+		io_req.notify.fn = NULL;
+	}
+	io_req.client = ic->io;
+	io_loc.bdev = ic->dev->bdev;
+	io_loc.sector = ic->start + SB_SECTORS + sector;
+	io_loc.count = n_sectors;
+
+	r = dm_io(&io_req, 1, &io_loc, NULL);
+	if (unlikely(r)) {
+		dm_integrity_io_error(ic, op == REQ_OP_READ ? "reading journal" : "writing journal", r);
+		if (comp) {
+			WARN_ONCE(1, "asynchronous dm_io failed: %d", r);
+			complete_journal_io(-1UL, comp);
+		}
+	}
+}
+
+static void write_journal(struct dm_integrity_c *ic, unsigned commit_start, unsigned commit_sections)
+{
+	struct journal_completion io_comp;
+	struct journal_completion crypt_comp_1;
+	struct journal_completion crypt_comp_2;
+	unsigned i;
+
+	io_comp.ic = ic;
+	io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp);
+
+	if (commit_start + commit_sections <= ic->journal_sections) {
+		io_comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+		if (ic->journal_io) {
+			crypt_comp_1.ic = ic;
+			crypt_comp_1.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_1.comp);
+			crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
+			encrypt_journal(ic, true, commit_start, commit_sections, &crypt_comp_1);
+			wait_for_completion_io(&crypt_comp_1.comp);
+		} else {
+			for (i = 0; i < commit_sections; i++)
+				rw_section_mac(ic, commit_start + i, true);
+		}
+		rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, commit_sections, &io_comp);
+	} else {
+		unsigned to_end;
+		io_comp.in_flight = (atomic_t)ATOMIC_INIT(2);
+		to_end = ic->journal_sections - commit_start;
+		if (ic->journal_io) {
+			crypt_comp_1.ic = ic;
+			crypt_comp_1.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_1.comp);
+			crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
+			encrypt_journal(ic, true, commit_start, to_end, &crypt_comp_1);
+			if (try_wait_for_completion(&crypt_comp_1.comp)) {
+				rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, to_end, &io_comp);
+				crypt_comp_1.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_1.comp);
+				crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
+				encrypt_journal(ic, true, 0, commit_sections - to_end, &crypt_comp_1);
+				wait_for_completion_io(&crypt_comp_1.comp);
+			} else {
+				crypt_comp_2.ic = ic;
+				crypt_comp_2.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_2.comp);
+				crypt_comp_2.in_flight = (atomic_t)ATOMIC_INIT(0);
+				encrypt_journal(ic, true, 0, commit_sections - to_end, &crypt_comp_2);
+				wait_for_completion_io(&crypt_comp_1.comp);
+				rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, to_end, &io_comp);
+				wait_for_completion_io(&crypt_comp_2.comp);
+			}
+		} else {
+			for (i = 0; i < to_end; i++)
+				rw_section_mac(ic, commit_start + i, true);
+			rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, to_end, &io_comp);
+			for (i = 0; i < commit_sections - to_end; i++)
+				rw_section_mac(ic, i, true);
+		}
+		rw_journal(ic, REQ_OP_WRITE, REQ_FUA, 0, commit_sections - to_end, &io_comp);
+	}
+
+	wait_for_completion_io(&io_comp.comp);
+}
+
+static void copy_from_journal(struct dm_integrity_c *ic, unsigned section, unsigned offset,
+			      unsigned n_sectors, sector_t target, io_notify_fn fn, void *data)
+{
+	struct dm_io_request io_req;
+	struct dm_io_region io_loc;
+	int r;
+	unsigned sector, pl_index, pl_offset;
+
+	if (unlikely(dm_integrity_failed(ic))) {
+		fn(-1UL, data);
+		return;
+	}
+
+	sector = section * ic->journal_section_sectors + JOURNAL_BLOCK_SECTORS + offset;
+
+	pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
+	pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
+
+	io_req.bi_op = REQ_OP_WRITE;
+	io_req.bi_op_flags = 0;
+	io_req.mem.type = DM_IO_PAGE_LIST;
+	io_req.mem.ptr.pl = &ic->journal[pl_index];
+	io_req.mem.offset = pl_offset;
+	io_req.notify.fn = fn;
+	io_req.notify.context = data;
+	io_req.client = ic->io;
+	io_loc.bdev = ic->dev->bdev;
+	io_loc.sector = ic->start + target;
+	io_loc.count = n_sectors;
+
+	r = dm_io(&io_req, 1, &io_loc, NULL);
+	if (unlikely(r)) {
+		WARN_ONCE(1, "asynchronous dm_io failed: %d", r);
+		fn(-1UL, data);
+	}
+}
+
+static bool add_new_range(struct dm_integrity_c *ic, struct dm_integrity_range *new_range)
+{
+	struct rb_node **n = &ic->in_progress.rb_node;
+	struct rb_node *parent;
+
+	parent = NULL;
+
+	while (*n) {
+		struct dm_integrity_range *range = container_of(*n, struct dm_integrity_range, node);
+
+		parent = *n;
+		if (new_range->logical_sector + new_range->n_sectors <= range->logical_sector) {
+			n = &range->node.rb_left;
+		} else if (new_range->logical_sector >= range->logical_sector + range->n_sectors) {
+			n = &range->node.rb_right;
+		} else {
+			return false;
+		}
+	}
+
+	rb_link_node(&new_range->node, parent, n);
+	rb_insert_color(&new_range->node, &ic->in_progress);
+
+	return true;
+}
+
+static void remove_range_unlocked(struct dm_integrity_c *ic, struct dm_integrity_range *range)
+{
+	rb_erase(&range->node, &ic->in_progress);
+	wake_up_locked(&ic->endio_wait);
+}
+
+static void remove_range(struct dm_integrity_c *ic, struct dm_integrity_range *range)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ic->endio_wait.lock, flags);
+	remove_range_unlocked(ic, range);
+	spin_unlock_irqrestore(&ic->endio_wait.lock, flags);
+}
+
+static void init_journal_node(struct journal_node *node)
+{
+	RB_CLEAR_NODE(&node->node);
+	node->sector = (sector_t)-1;
+}
+
+static void add_journal_node(struct dm_integrity_c *ic, struct journal_node *node, sector_t sector)
+{
+	struct rb_node **link;
+	struct rb_node *parent;
+
+	node->sector = sector;
+	BUG_ON(!RB_EMPTY_NODE(&node->node));
+
+	link = &ic->journal_tree_root.rb_node;
+	parent = NULL;
+
+	while (*link) {
+		struct journal_node *j;
+		parent = *link;
+		j = container_of(parent, struct journal_node, node);
+		if (sector < j->sector)
+			link = &j->node.rb_left;
+		else
+			link = &j->node.rb_right;
+	}
+
+	rb_link_node(&node->node, parent, link);
+	rb_insert_color(&node->node, &ic->journal_tree_root);
+}
+
+static void remove_journal_node(struct dm_integrity_c *ic, struct journal_node *node)
+{
+	BUG_ON(RB_EMPTY_NODE(&node->node));
+	rb_erase(&node->node, &ic->journal_tree_root);
+	init_journal_node(node);
+}
+
+#define NOT_FOUND	(-1U)
+
+static unsigned find_journal_node(struct dm_integrity_c *ic, sector_t sector, sector_t *next_sector)
+{
+	struct rb_node *n = ic->journal_tree_root.rb_node;
+	unsigned found = NOT_FOUND;
+	*next_sector = (sector_t)-1;
+	while (n) {
+		struct journal_node *j = container_of(n, struct journal_node, node);
+		if (sector == j->sector) {
+			found = j - ic->journal_tree;
+		}
+		if (sector < j->sector) {
+			*next_sector = j->sector;
+			n = j->node.rb_left;
+		} else {
+			n = j->node.rb_right;
+		}
+	}
+
+	return found;
+}
+
+static bool test_journal_node(struct dm_integrity_c *ic, unsigned pos, sector_t sector)
+{
+	struct journal_node *node, *next_node;
+	struct rb_node *next;
+
+	if (unlikely(pos >= ic->journal_entries))
+		return false;
+	node = &ic->journal_tree[pos];
+	if (unlikely(RB_EMPTY_NODE(&node->node)))
+		return false;
+	if (unlikely(node->sector != sector))
+		return false;
+
+	next = rb_next(&node->node);
+	if (unlikely(!next))
+		return true;
+
+	next_node = container_of(next, struct journal_node, node);
+	return next_node->sector != sector;
+}
+
+static bool find_newer_committed_node(struct dm_integrity_c *ic, struct journal_node *node)
+{
+	struct rb_node *next;
+	struct journal_node *next_node;
+	unsigned next_section;
+
+	BUG_ON(RB_EMPTY_NODE(&node->node));
+
+	next = rb_next(&node->node);
+	if (unlikely(!next))
+		return false;
+
+	next_node = container_of(next, struct journal_node, node);
+
+	if (next_node->sector != node->sector)
+		return false;
+
+	next_section = (unsigned)(next_node - ic->journal_tree) / ic->journal_section_entries;
+	if (next_section >= ic->committed_section &&
+	    next_section < ic->committed_section + ic->n_committed_sections)
+		return true;
+	if (next_section + ic->journal_sections < ic->committed_section + ic->n_committed_sections)
+		return true;
+
+	return false;
+}
+
+#define TAG_READ	0
+#define TAG_WRITE	1
+#define TAG_CMP		2
+
+static int dm_integrity_rw_tag(struct dm_integrity_c *ic, unsigned char *tag, sector_t *metadata_block,
+			       unsigned *metadata_offset, unsigned total_size, int op)
+{
+	do {
+		unsigned char *data, *dp;
+		struct dm_buffer *b;
+		unsigned to_copy;
+		int r;
+
+		r = dm_integrity_failed(ic);
+		if (unlikely(r))
+			return r;
+
+		data = dm_bufio_read(ic->bufio, *metadata_block, &b);
+		if (unlikely(IS_ERR(data)))
+			return PTR_ERR(data);
+
+		to_copy = min((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - *metadata_offset, total_size);
+		dp = data + *metadata_offset;
+		if (op == TAG_READ) {
+			memcpy(tag, dp, to_copy);
+		} else if (op == TAG_WRITE) {
+			memcpy(dp, tag, to_copy);
+			dm_bufio_mark_buffer_dirty(b);
+		} else  {
+			/* e.g.: op == TAG_CMP */
+			if (unlikely(memcmp(dp, tag, to_copy))) {
+				unsigned i;
+
+				for (i = 0; i < to_copy; i++) {
+					if (dp[i] != tag[i])
+						break;
+					total_size--;
+				}
+				dm_bufio_release(b);
+				return total_size;
+			}
+		}
+		dm_bufio_release(b);
+
+		tag += to_copy;
+		*metadata_offset += to_copy;
+		if (unlikely(*metadata_offset == 1U << SECTOR_SHIFT << ic->log2_buffer_sectors)) {
+			(*metadata_block)++;
+			*metadata_offset = 0;
+		}
+		total_size -= to_copy;
+	} while (unlikely(total_size));
+
+	return 0;
+}
+
+static void dm_integrity_flush_buffers(struct dm_integrity_c *ic)
+{
+	int r;
+	r = dm_bufio_write_dirty_buffers(ic->bufio);
+	if (unlikely(r))
+		dm_integrity_io_error(ic, "writing tags", r);
+}
+
+static void sleep_on_endio_wait(struct dm_integrity_c *ic)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	__add_wait_queue(&ic->endio_wait, &wait);
+	__set_current_state(TASK_UNINTERRUPTIBLE);
+	spin_unlock_irq(&ic->endio_wait.lock);
+	io_schedule();
+	spin_lock_irq(&ic->endio_wait.lock);
+	__remove_wait_queue(&ic->endio_wait, &wait);
+}
+
+static void autocommit_fn(unsigned long data)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)data;
+
+	if (likely(!dm_integrity_failed(ic)))
+		queue_work(ic->commit_wq, &ic->commit_work);
+}
+
+static void schedule_autocommit(struct dm_integrity_c *ic)
+{
+	if (!timer_pending(&ic->autocommit_timer))
+		mod_timer(&ic->autocommit_timer, jiffies + ic->autocommit_jiffies);
+}
+
+static void submit_flush_bio(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
+{
+	struct bio *bio;
+	spin_lock_irq(&ic->endio_wait.lock);
+	bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+	bio_list_add(&ic->flush_bio_list, bio);
+	spin_unlock_irq(&ic->endio_wait.lock);
+	queue_work(ic->commit_wq, &ic->commit_work);
+}
+
+static void do_endio(struct dm_integrity_c *ic, struct bio *bio)
+{
+	int r = dm_integrity_failed(ic);
+	if (unlikely(r) && !bio->bi_error)
+		bio->bi_error = r;
+	bio_endio(bio);
+}
+
+static void do_endio_flush(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
+{
+	struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+
+	if (unlikely(dio->fua) && likely(!bio->bi_error) && likely(!dm_integrity_failed(ic)))
+		submit_flush_bio(ic, dio);
+	else
+		do_endio(ic, bio);
+}
+
+static void dec_in_flight(struct dm_integrity_io *dio)
+{
+	if (atomic_dec_and_test(&dio->in_flight)) {
+		struct dm_integrity_c *ic = dio->ic;
+		struct bio *bio;
+
+		remove_range(ic, &dio->range);
+
+		if (unlikely(dio->write))
+			schedule_autocommit(ic);
+
+		bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+
+		if (unlikely(dio->bi_error) && !bio->bi_error)
+			bio->bi_error = dio->bi_error;
+		if (likely(!bio->bi_error) && unlikely(bio_sectors(bio) != dio->range.n_sectors)) {
+			dio->range.logical_sector += dio->range.n_sectors;
+			bio_advance(bio, dio->range.n_sectors << SECTOR_SHIFT);
+			INIT_WORK(&dio->work, integrity_bio_wait);
+			queue_work(ic->wait_wq, &dio->work);
+			return;
+		}
+		do_endio_flush(ic, dio);
+	}
+}
+
+static void integrity_end_io(struct bio *bio)
+{
+	struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
+
+	bio->bi_iter = dio->orig_bi_iter;
+	bio->bi_bdev = dio->orig_bi_bdev;
+	if (dio->orig_bi_integrity) {
+		bio->bi_integrity = dio->orig_bi_integrity;
+		bio->bi_opf |= REQ_INTEGRITY;
+	}
+	bio->bi_end_io = dio->orig_bi_end_io;
+
+	if (dio->completion)
+		complete(dio->completion);
+
+	dec_in_flight(dio);
+}
+
+static void integrity_sector_checksum(struct dm_integrity_c *ic, sector_t sector,
+				      const char *data, char *result)
+{
+	__u64 sector_le = cpu_to_le64(sector);
+	SHASH_DESC_ON_STACK(req, ic->internal_hash);
+	int r;
+	unsigned digest_size;
+
+	req->tfm = ic->internal_hash;
+	req->flags = 0;
+
+	r = crypto_shash_init(req);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_init", r);
+		goto failed;
+	}
+
+	r = crypto_shash_update(req, (const __u8 *)&sector_le, sizeof sector_le);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_update", r);
+		goto failed;
+	}
+
+	r = crypto_shash_update(req, data, 1 << SECTOR_SHIFT);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_update", r);
+		goto failed;
+	}
+
+	r = crypto_shash_final(req, result);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_final", r);
+		goto failed;
+	}
+
+	digest_size = crypto_shash_digestsize(ic->internal_hash);
+	if (unlikely(digest_size < ic->tag_size))
+		memset(result + digest_size, 0, ic->tag_size - digest_size);
+
+	return;
+
+failed:
+	/* this shouldn't happen anyway, the hash functions have no reason to fail */
+	get_random_bytes(result, ic->tag_size);
+}
+
+static void integrity_metadata(struct work_struct *w)
+{
+	struct dm_integrity_io *dio = container_of(w, struct dm_integrity_io, work);
+	struct dm_integrity_c *ic = dio->ic;
+
+	int r;
+
+	if (ic->internal_hash) {
+		struct bvec_iter iter;
+		struct bio_vec bv;
+		unsigned digest_size = crypto_shash_digestsize(ic->internal_hash);
+		struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+		char *checksums;
+		unsigned extra_space = digest_size > ic->tag_size ? digest_size - ic->tag_size : 0;
+		char checksums_onstack[ic->tag_size + extra_space];
+		unsigned sectors_to_process = dio->range.n_sectors;
+		sector_t sector = dio->range.logical_sector;
+
+		checksums = kmalloc((PAGE_SIZE >> SECTOR_SHIFT) * ic->tag_size + extra_space,
+				    GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
+		if (!checksums)
+			checksums = checksums_onstack;
+
+		__bio_for_each_segment(bv, bio, iter, dio->orig_bi_iter) {
+			unsigned pos;
+			char *mem, *checksums_ptr;
+
+again:
+			mem = (char *)kmap_atomic(bv.bv_page) + bv.bv_offset;
+			pos = 0;
+			checksums_ptr = checksums;
+			do {
+				integrity_sector_checksum(ic, sector, mem + pos, checksums_ptr);
+				checksums_ptr += ic->tag_size;
+				sectors_to_process--;
+				pos += 1 << SECTOR_SHIFT;
+				sector++;
+			} while (pos < bv.bv_len && sectors_to_process && checksums != checksums_onstack);
+			kunmap_atomic(mem);
+
+			r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
+						checksums_ptr - checksums, !dio->write ? TAG_CMP : TAG_WRITE);
+			if (unlikely(r)) {
+				if (r > 0) {
+					DMERR("Checksum failed at sector 0x%llx",
+					      (unsigned long long)(sector - ((r + ic->tag_size - 1) / ic->tag_size)));
+					r = -EILSEQ;
+				}
+				if (likely(checksums != checksums_onstack))
+					kfree(checksums);
+				goto error;
+			}
+
+			if (!sectors_to_process)
+				break;
+
+			if (unlikely(pos < bv.bv_len)) {
+				bv.bv_offset += pos;
+				bv.bv_len -= pos;
+				goto again;
+			}
+		}
+
+		if (likely(checksums != checksums_onstack))
+			kfree(checksums);
+	} else {
+		struct bio_integrity_payload *bip = dio->orig_bi_integrity;
+
+		if (bip) {
+			struct bio_vec biv;
+			struct bvec_iter iter;
+			unsigned data_to_process = dio->range.n_sectors * ic->tag_size;
+
+			bip_for_each_vec(biv, bip, iter) {
+				unsigned char *tag;
+				unsigned this_len;
+
+				BUG_ON(PageHighMem(biv.bv_page));
+				tag = lowmem_page_address(biv.bv_page) + biv.bv_offset;
+				this_len = min(biv.bv_len, data_to_process);
+				r = dm_integrity_rw_tag(ic, tag, &dio->metadata_block, &dio->metadata_offset,
+							this_len, !dio->write ? TAG_READ : TAG_WRITE);
+				if (unlikely(r))
+					goto error;
+				data_to_process -= this_len;
+				if (!data_to_process)
+					break;
+			}
+		}
+	}
+	dec_in_flight(dio);
+	return;
+error:
+	dio->bi_error = r;
+	dec_in_flight(dio);
+}
+
+static int dm_integrity_map(struct dm_target *ti, struct bio *bio)
+{
+	struct dm_integrity_c *ic = ti->private;
+	struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
+
+	sector_t area, offset;
+
+	dio->ic = ic;
+	dio->bi_error = 0;
+
+	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+		submit_flush_bio(ic, dio);
+		return DM_MAPIO_SUBMITTED;
+	}
+
+	dio->range.logical_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
+	dio->write = bio_op(bio) == REQ_OP_WRITE;
+	dio->fua = dio->write && bio->bi_opf & REQ_FUA;
+	if (unlikely(dio->fua)) {
+		/*
+		 * Don't pass down the FUA flag because we have to flush
+		 * disk cache anyway.
+		 */
+		bio->bi_opf &= ~REQ_FUA;
+	}
+	if (unlikely(dio->range.logical_sector + bio_sectors(bio) > ic->provided_data_sectors)) {
+		DMERR("Too big sector number: 0x%llx + 0x%x > 0x%llx",
+		      (unsigned long long)dio->range.logical_sector, bio_sectors(bio),
+		      (unsigned long long)ic->provided_data_sectors);
+		return -EIO;
+	}
+
+	get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
+	dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset, &dio->metadata_offset);
+	bio->bi_iter.bi_sector = get_data_sector(ic, area, offset);
+
+	dm_integrity_map_continue(dio, true);
+	return DM_MAPIO_SUBMITTED;
+}
+
+static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio,
+				 unsigned journal_section, unsigned journal_entry)
+{
+	struct dm_integrity_c *ic = dio->ic;
+	sector_t logical_sector;
+	unsigned n_sectors;
+
+	logical_sector = dio->range.logical_sector;
+	n_sectors = dio->range.n_sectors;
+	do {
+		struct bio_vec bv = bio_iovec(bio);
+		char *mem;
+
+		if (unlikely(bv.bv_len >> SECTOR_SHIFT > n_sectors))
+			bv.bv_len = n_sectors << SECTOR_SHIFT;
+		n_sectors -= bv.bv_len >> SECTOR_SHIFT;
+		bio_advance_iter(bio, &bio->bi_iter, bv.bv_len);
+retry_kmap:
+		mem = kmap_atomic(bv.bv_page);
+		if (likely(dio->write))
+			flush_dcache_page(bv.bv_page);
+
+		do {
+			struct journal_entry *je = access_journal_entry(ic, journal_section, journal_entry);
+
+			if (unlikely(!dio->write)) {
+				struct journal_sector *js;
+
+				if (unlikely(journal_entry_is_inprogress(je))) {
+					flush_dcache_page(bv.bv_page);
+					kunmap_atomic(mem);
+
+					__io_wait_event(ic->copy_to_journal_wait, !journal_entry_is_inprogress(je));
+					goto retry_kmap;
+				}
+				smp_rmb();
+				BUG_ON(journal_entry_get_sector(je) != logical_sector);
+				js = access_journal_data(ic, journal_section, journal_entry);
+				memcpy(mem + bv.bv_offset, js, JOURNAL_SECTOR_DATA);
+				memcpy(mem + bv.bv_offset + JOURNAL_SECTOR_DATA, &je->last_bytes, sizeof je->last_bytes);
+#ifdef INTERNAL_VERIFY
+				if (ic->internal_hash) {
+					char checksums_onstack[max(crypto_shash_digestsize(ic->internal_hash), ic->tag_size)];
+
+					integrity_sector_checksum(ic, logical_sector, mem + bv.bv_offset, checksums_onstack);
+					if (unlikely(memcmp(checksums_onstack, je->tag, ic->tag_size))) {
+						DMERR("Checksum failed when reading from journal, at sector 0x%llx",
+						      (unsigned long long)logical_sector);
+					}
+				}
+#endif
+			}
+
+			if (!ic->internal_hash) {
+				struct bio_integrity_payload *bip = bio_integrity(bio);
+				unsigned tag_todo = ic->tag_size;
+				char *tag_ptr = je->tag;
+
+				if (bip) do {
+					struct bio_vec biv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+					unsigned tag_now = min(biv.bv_len, tag_todo);
+					char *tag_addr;
+					BUG_ON(PageHighMem(biv.bv_page));
+					tag_addr = lowmem_page_address(biv.bv_page) + biv.bv_offset;
+					if (likely(dio->write))
+						memcpy(tag_ptr, tag_addr, tag_now);
+					else
+						memcpy(tag_addr, tag_ptr, tag_now);
+					bvec_iter_advance(bip->bip_vec, &bip->bip_iter, tag_now);
+					tag_ptr += tag_now;
+					tag_todo -= tag_now;
+				} while (unlikely(tag_todo)); else {
+					if (likely(dio->write))
+						memset(tag_ptr, 0, tag_todo);
+				}
+			}
+
+			if (likely(dio->write)) {
+				struct journal_sector *js;
+
+				js = access_journal_data(ic, journal_section, journal_entry);
+				memcpy(js, mem + bv.bv_offset, 1 << SECTOR_SHIFT);
+				je->last_bytes = js->commit_id;
+
+				if (ic->internal_hash) {
+					unsigned digest_size = crypto_shash_digestsize(ic->internal_hash);
+					if (unlikely(digest_size > ic->tag_size)) {
+						char checksums_onstack[digest_size];
+						integrity_sector_checksum(ic, logical_sector, (char *)js, checksums_onstack);
+						memcpy(je->tag, checksums_onstack, ic->tag_size);
+					} else
+						integrity_sector_checksum(ic, logical_sector, (char *)js, je->tag);
+				}
+
+				journal_entry_set_sector(je, logical_sector);
+			}
+			logical_sector++;
+
+			journal_entry++;
+			if (unlikely(journal_entry == ic->journal_section_entries)) {
+				journal_entry = 0;
+				journal_section++;
+				wraparound_section(ic, &journal_section);
+			}
+
+			bv.bv_offset += 1 << SECTOR_SHIFT;
+		} while (bv.bv_len -= 1 << SECTOR_SHIFT);
+
+		if (unlikely(!dio->write))
+			flush_dcache_page(bv.bv_page);
+		kunmap_atomic(mem);
+	} while (n_sectors);
+
+	if (likely(dio->write)) {
+		smp_mb();
+		if (unlikely(waitqueue_active(&ic->copy_to_journal_wait)))
+			wake_up(&ic->copy_to_journal_wait);
+		if (ACCESS_ONCE(ic->free_sectors) <= ic->free_sectors_threshold) {
+			queue_work(ic->commit_wq, &ic->commit_work);
+		} else {
+			schedule_autocommit(ic);
+		}
+	} else {
+		remove_range(ic, &dio->range);
+	}
+
+	if (unlikely(bio->bi_iter.bi_size)) {
+		sector_t area, offset;
+
+		dio->range.logical_sector = logical_sector;
+		get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
+		dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset, &dio->metadata_offset);
+		return true;
+	}
+
+	return false;
+}
+
+static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map)
+{
+	struct dm_integrity_c *ic = dio->ic;
+	struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+	unsigned journal_section, journal_entry;
+	unsigned journal_read_pos;
+	struct completion read_comp;
+	bool need_sync_io = ic->internal_hash && !dio->write;
+
+	if (need_sync_io && from_map) {
+		INIT_WORK(&dio->work, integrity_bio_wait);
+		queue_work(ic->metadata_wq, &dio->work);
+		return;
+	}
+
+lock_retry:
+	spin_lock_irq(&ic->endio_wait.lock);
+retry:
+	if (unlikely(dm_integrity_failed(ic))) {
+		spin_unlock_irq(&ic->endio_wait.lock);
+		do_endio(ic, bio);
+		return;
+	}
+	dio->range.n_sectors = bio_sectors(bio);
+	journal_read_pos = NOT_FOUND;
+	if (likely(ic->mode == 'J')) {
+		if (dio->write) {
+			unsigned next_entry, i, pos;
+			unsigned ws, we;
+
+			dio->range.n_sectors = min(dio->range.n_sectors, ic->free_sectors);
+			if (unlikely(!dio->range.n_sectors))
+				goto sleep;
+			ic->free_sectors -= dio->range.n_sectors;
+			journal_section = ic->free_section;
+			journal_entry = ic->free_section_entry;
+
+			next_entry = ic->free_section_entry + dio->range.n_sectors;
+			ic->free_section_entry = next_entry % ic->journal_section_entries;
+			ic->free_section += next_entry / ic->journal_section_entries;
+			ic->n_uncommitted_sections += next_entry / ic->journal_section_entries;
+			wraparound_section(ic, &ic->free_section);
+
+			pos = journal_section * ic->journal_section_entries + journal_entry;
+			ws = journal_section;
+			we = journal_entry;
+			for (i = 0; i < dio->range.n_sectors; i++) {
+				struct journal_entry *je;
+
+				add_journal_node(ic, &ic->journal_tree[pos], dio->range.logical_sector + i);
+				pos++;
+				if (unlikely(pos >= ic->journal_entries))
+					pos = 0;
+
+				je = access_journal_entry(ic, ws, we);
+				BUG_ON(!journal_entry_is_unused(je));
+				journal_entry_set_inprogress(je);
+				we++;
+				if (unlikely(we == ic->journal_section_entries)) {
+					we = 0;
+					ws++;
+					wraparound_section(ic, &ws);
+				}
+			}
+
+			spin_unlock_irq(&ic->endio_wait.lock);
+			goto journal_read_write;
+		} else {
+			sector_t next_sector;
+			journal_read_pos = find_journal_node(ic, dio->range.logical_sector, &next_sector);
+			if (likely(journal_read_pos == NOT_FOUND)) {
+				if (unlikely(dio->range.n_sectors > next_sector - dio->range.logical_sector))
+					dio->range.n_sectors = next_sector - dio->range.logical_sector;
+			} else {
+				unsigned i;
+				for (i = 1; i < dio->range.n_sectors; i++) {
+					if (!test_journal_node(ic, journal_read_pos + i, dio->range.logical_sector + i))
+						break;
+				}
+				dio->range.n_sectors = i;
+			}
+		}
+	}
+	if (unlikely(!add_new_range(ic, &dio->range))) {
+		/*
+		 * We must not sleep in the request routine because it could
+		 * stall bios on current->bio_list.
+		 * So, we offload the bio to a workqueue if we have to sleep.
+		 */
+sleep:
+		if (from_map) {
+			spin_unlock_irq(&ic->endio_wait.lock);
+			INIT_WORK(&dio->work, integrity_bio_wait);
+			queue_work(ic->wait_wq, &dio->work);
+			return;
+		} else {
+			sleep_on_endio_wait(ic);
+			goto retry;
+		}
+	}
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (unlikely(journal_read_pos != NOT_FOUND)) {
+		journal_section = journal_read_pos / ic->journal_section_entries;
+		journal_entry = journal_read_pos % ic->journal_section_entries;
+		goto journal_read_write;
+	}
+
+	dio->in_flight = (atomic_t)ATOMIC_INIT(2);
+
+	if (need_sync_io) {
+		read_comp = COMPLETION_INITIALIZER_ONSTACK(read_comp);
+		dio->completion = &read_comp;
+	} else
+		dio->completion = NULL;
+
+	dio->orig_bi_iter = bio->bi_iter;
+
+	dio->orig_bi_bdev = bio->bi_bdev;
+	bio->bi_bdev = ic->dev->bdev;
+
+	dio->orig_bi_integrity = bio_integrity(bio);
+	bio->bi_integrity = NULL;
+	bio->bi_opf &= ~REQ_INTEGRITY;
+
+	dio->orig_bi_end_io = bio->bi_end_io;
+	bio->bi_end_io = integrity_end_io;
+
+	bio->bi_iter.bi_size = dio->range.n_sectors << SECTOR_SHIFT;
+	bio->bi_iter.bi_sector += ic->start;
+	generic_make_request(bio);
+
+	if (need_sync_io) {
+		wait_for_completion_io(&read_comp);
+		integrity_metadata(&dio->work);
+	} else {
+		INIT_WORK(&dio->work, integrity_metadata);
+		queue_work(ic->metadata_wq, &dio->work);
+	}
+
+	return;
+
+journal_read_write:
+	if (unlikely(__journal_read_write(dio, bio, journal_section, journal_entry)))
+		goto lock_retry;
+
+	do_endio_flush(ic, dio);
+}
+
+
+static void integrity_bio_wait(struct work_struct *w)
+{
+	struct dm_integrity_io *dio = container_of(w, struct dm_integrity_io, work);
+
+	dm_integrity_map_continue(dio, false);
+}
+
+static void pad_uncommitted(struct dm_integrity_c *ic)
+{
+	if (ic->free_section_entry) {
+		ic->free_sectors -= ic->journal_section_entries - ic->free_section_entry;
+		ic->free_section_entry = 0;
+		ic->free_section++;
+		wraparound_section(ic, &ic->free_section);
+		ic->n_uncommitted_sections++;
+	}
+}
+
+static void integrity_commit(struct work_struct *w)
+{
+	struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, commit_work);
+	unsigned commit_start, commit_sections;
+	unsigned i, j, n;
+	struct bio *flushes;
+
+	del_timer(&ic->autocommit_timer);
+
+	spin_lock_irq(&ic->endio_wait.lock);
+	flushes = bio_list_get(&ic->flush_bio_list);
+	if (unlikely(ic->mode != 'J')) {
+		spin_unlock_irq(&ic->endio_wait.lock);
+		dm_integrity_flush_buffers(ic);
+		goto release_flush_bios;
+	}
+
+	pad_uncommitted(ic);
+	commit_start = ic->uncommitted_section;
+	commit_sections = ic->n_uncommitted_sections;
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (!commit_sections)
+		goto release_flush_bios;
+
+	i = commit_start;
+	for (n = 0; n < commit_sections; n++) {
+		for (j = 0; j < ic->journal_section_entries; j++) {
+			struct journal_entry *je;
+			je = access_journal_entry(ic, i, j);
+			io_wait_event(ic->copy_to_journal_wait, !journal_entry_is_inprogress(je));
+		}
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			struct journal_sector *js;
+			js = access_journal(ic, i, j);
+			js->commit_id = dm_integrity_commit_id(ic, i, j, ic->commit_seq);
+		}
+		i++;
+		if (unlikely(i >= ic->journal_sections))
+			ic->commit_seq = next_commit_seq(ic->commit_seq);
+		wraparound_section(ic, &i);
+	}
+	smp_rmb();
+
+	write_journal(ic, commit_start, commit_sections);
+
+	spin_lock_irq(&ic->endio_wait.lock);
+	ic->uncommitted_section += commit_sections;
+	wraparound_section(ic, &ic->uncommitted_section);
+	ic->n_uncommitted_sections -= commit_sections;
+	ic->n_committed_sections += commit_sections;
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (ACCESS_ONCE(ic->free_sectors) <= ic->free_sectors_threshold)
+		queue_work(ic->writer_wq, &ic->writer_work);
+
+release_flush_bios:
+	while (flushes) {
+		struct bio *next = flushes->bi_next;
+		flushes->bi_next = NULL;
+		do_endio(ic, flushes);
+		flushes = next;
+	}
+}
+
+static void complete_copy_from_journal(unsigned long error, void *context)
+{
+	struct journal_io *io = context;
+	struct journal_completion *comp = io->comp;
+	struct dm_integrity_c *ic = comp->ic;
+	remove_range(ic, &io->range);
+	mempool_free(io, ic->journal_io_mempool);
+	if (unlikely(error != 0))
+		dm_integrity_io_error(ic, "copying from journal", -EIO);
+	complete_journal_op(comp);
+}
+
+static void do_journal_write(struct dm_integrity_c *ic, unsigned write_start,
+			     unsigned write_sections, bool from_replay)
+{
+	unsigned i, j, n;
+	struct journal_completion comp;
+
+	comp.ic = ic;
+	comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+	comp.comp = COMPLETION_INITIALIZER_ONSTACK(comp.comp);
+
+	i = write_start;
+	for (n = 0; n < write_sections; n++, i++, wraparound_section(ic, &i)) {
+#ifndef INTERNAL_VERIFY
+		if (unlikely(from_replay))
+#endif
+			rw_section_mac(ic, i, false);
+		for (j = 0; j < ic->journal_section_entries; j++) {
+			struct journal_entry *je = access_journal_entry(ic, i, j);
+			sector_t sec, area, offset;
+			unsigned k, l, next_loop;
+			sector_t metadata_block;
+			unsigned metadata_offset;
+			struct journal_io *io;
+
+			if (journal_entry_is_unused(je))
+				continue;
+			BUG_ON(unlikely(journal_entry_is_inprogress(je)) && !from_replay);
+			sec = journal_entry_get_sector(je);
+			get_area_and_offset(ic, sec, &area, &offset);
+			access_journal_data(ic, i, j)->commit_id = je->last_bytes;
+			for (k = j + 1; k < ic->journal_section_entries; k++) {
+				struct journal_entry *je2 = access_journal_entry(ic, i, k);
+				sector_t sec2, area2, offset2;
+				if (journal_entry_is_unused(je2))
+					break;
+				BUG_ON(unlikely(journal_entry_is_inprogress(je2)) && !from_replay);
+				sec2 = journal_entry_get_sector(je2);
+				get_area_and_offset(ic, sec2, &area2, &offset2);
+				if (area2 != area || offset2 != offset + (k - j))
+					break;
+				access_journal_data(ic, i, k)->commit_id = je2->last_bytes;
+			}
+			next_loop = k - 1;
+
+			io = mempool_alloc(ic->journal_io_mempool, GFP_NOIO);
+			io->comp = &comp;
+			io->range.logical_sector = sec;
+			io->range.n_sectors = k - j;
+
+			spin_lock_irq(&ic->endio_wait.lock);
+			while (unlikely(!add_new_range(ic, &io->range)))
+				sleep_on_endio_wait(ic);
+
+			if (likely(!from_replay)) {
+				struct journal_node *section_node = &ic->journal_tree[i * ic->journal_section_entries];
+
+				/* don't write if there is newer committed sector */
+				while (j < k && find_newer_committed_node(ic, &section_node[j])) {
+					struct journal_entry *je2 = access_journal_entry(ic, i, j);
+
+					journal_entry_set_unused(je2);
+					remove_journal_node(ic, &section_node[j]);
+					j++;
+					sec++;
+					offset++;
+				}
+				while (j < k && find_newer_committed_node(ic, &section_node[k - 1])) {
+					struct journal_entry *je2 = access_journal_entry(ic, i, k - 1);
+
+					journal_entry_set_unused(je2);
+					remove_journal_node(ic, &section_node[k - 1]);
+					k--;
+				}
+				if (j == k) {
+					remove_range_unlocked(ic, &io->range);
+					spin_unlock_irq(&ic->endio_wait.lock);
+					mempool_free(io, ic->journal_io_mempool);
+					goto skip_io;
+				}
+				for (l = j; l < k; l++) {
+					remove_journal_node(ic, &section_node[l]);
+				}
+			}
+			spin_unlock_irq(&ic->endio_wait.lock);
+
+			metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset);
+			for (l = j; l < k; l++) {
+				int r;
+				struct journal_entry *je2 = access_journal_entry(ic, i, l);
+
+				if (
+#ifndef INTERNAL_VERIFY
+				    unlikely(from_replay) &&
+#endif
+				    ic->internal_hash) {
+					unsigned char test_tag[ic->tag_size];
+
+					integrity_sector_checksum(ic, sec + (l - j),
+								  (char *)access_journal_data(ic, i, l), test_tag);
+					if (unlikely(memcmp(test_tag, je2->tag, ic->tag_size)))
+						dm_integrity_io_error(ic, "tag mismatch when replaying journal", -EILSEQ);
+				}
+
+				journal_entry_set_unused(je2);
+				r = dm_integrity_rw_tag(ic, je2->tag, &metadata_block, &metadata_offset,
+							ic->tag_size, TAG_WRITE);
+				if (unlikely(r)) {
+					dm_integrity_io_error(ic, "reading tags", r);
+				}
+			}
+
+			atomic_inc(&comp.in_flight);
+			copy_from_journal(ic, i, j, k - j, get_data_sector(ic, area, offset),
+					  complete_copy_from_journal, io);
+skip_io:
+			j = next_loop;
+		}
+	}
+
+	dm_bufio_write_dirty_buffers_async(ic->bufio);
+
+	complete_journal_op(&comp);
+	wait_for_completion_io(&comp.comp);
+
+	dm_integrity_flush_buffers(ic);
+}
+
+static void integrity_writer(struct work_struct *w)
+{
+	struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, writer_work);
+	unsigned write_start, write_sections;
+
+	unsigned prev_free_sectors;
+
+	/* the following test is not needed, but it tests the replay code */
+	if (ACCESS_ONCE(ic->suspending))
+		return;
+
+	spin_lock_irq(&ic->endio_wait.lock);
+	write_start = ic->committed_section;
+	write_sections = ic->n_committed_sections;
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (!write_sections)
+		return;
+
+	do_journal_write(ic, write_start, write_sections, false);
+
+	spin_lock_irq(&ic->endio_wait.lock);
+
+	ic->committed_section += write_sections;
+	wraparound_section(ic, &ic->committed_section);
+	ic->n_committed_sections -= write_sections;
+
+	prev_free_sectors = ic->free_sectors;
+	ic->free_sectors += write_sections * ic->journal_section_entries;
+	if (unlikely(!prev_free_sectors))
+		wake_up_locked(&ic->endio_wait);
+
+	spin_unlock_irq(&ic->endio_wait.lock);
+}
+
+static void init_journal(struct dm_integrity_c *ic, unsigned start_section,
+			 unsigned n_sections, unsigned char commit_seq)
+{
+	unsigned i, j, n;
+
+	if (!n_sections)
+		return;
+
+	for (n = 0; n < n_sections; n++) {
+		i = start_section + n;
+		wraparound_section(ic, &i);
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			struct journal_sector *js = access_journal(ic, i, j);
+			memset(&js->entries, 0, JOURNAL_SECTOR_DATA);
+			js->commit_id = dm_integrity_commit_id(ic, i, j, commit_seq);
+		}
+		for (j = 0; j < ic->journal_section_entries; j++) {
+			struct journal_entry *je = access_journal_entry(ic, i, j);
+			journal_entry_set_unused(je);
+		}
+	}
+
+	write_journal(ic, start_section, n_sections);
+}
+
+static int find_commit_seq(struct dm_integrity_c *ic, unsigned i, unsigned j, commit_id_t id)
+{
+	unsigned char k;
+	for (k = 0; k < N_COMMIT_IDS; k++) {
+		if (dm_integrity_commit_id(ic, i, j, k) == id)
+			return k;
+	}
+	dm_integrity_io_error(ic, "journal commit id", -EIO);
+	return -EIO;
+}
+
+static void replay_journal(struct dm_integrity_c *ic)
+{
+	unsigned i, j;
+	bool used_commit_ids[N_COMMIT_IDS];
+	unsigned max_commit_id_sections[N_COMMIT_IDS];
+	unsigned write_start, write_sections;
+	unsigned continue_section;
+	bool journal_empty;
+	unsigned char unused, last_used, want_commit_seq;
+
+	if (ic->journal_uptodate)
+		return;
+
+	last_used = 0;
+	write_start = 0;
+
+	if (!ic->just_formatted) {
+		DEBUG_print("reading journal\n");
+		rw_journal(ic, REQ_OP_READ, 0, 0, ic->journal_sections, NULL);
+		if (ic->journal_io)
+			DEBUG_bytes(lowmem_page_address(ic->journal_io[0].page), 64, "read journal");
+		if (ic->journal_io) {
+			struct journal_completion crypt_comp;
+			crypt_comp.ic = ic;
+			crypt_comp.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp.comp);
+			crypt_comp.in_flight = (atomic_t)ATOMIC_INIT(0);
+			encrypt_journal(ic, false, 0, ic->journal_sections, &crypt_comp);
+			wait_for_completion(&crypt_comp.comp);
+		}
+		DEBUG_bytes(lowmem_page_address(ic->journal[0].page), 64, "decrypted journal");
+	}
+
+	if (dm_integrity_failed(ic))
+		goto clear_journal;
+
+	journal_empty = true;
+	memset(used_commit_ids, 0, sizeof used_commit_ids);
+	memset(max_commit_id_sections, 0, sizeof max_commit_id_sections);
+	for (i = 0; i < ic->journal_sections; i++) {
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			int k;
+			struct journal_sector *js = access_journal(ic, i, j);
+			k = find_commit_seq(ic, i, j, js->commit_id);
+			if (k < 0)
+				goto clear_journal;
+			used_commit_ids[k] = true;
+			max_commit_id_sections[k] = i;
+		}
+		if (journal_empty) {
+			for (j = 0; j < ic->journal_section_entries; j++) {
+				struct journal_entry *je = access_journal_entry(ic, i, j);
+				if (!journal_entry_is_unused(je)) {
+					journal_empty = false;
+					break;
+				}
+			}
+		}
+	}
+
+	if (!used_commit_ids[N_COMMIT_IDS - 1]) {
+		unused = N_COMMIT_IDS - 1;
+		while (unused && !used_commit_ids[unused - 1])
+			unused--;
+	} else {
+		for (unused = 0; unused < N_COMMIT_IDS; unused++)
+			if (!used_commit_ids[unused])
+				break;
+		if (unused == N_COMMIT_IDS) {
+			dm_integrity_io_error(ic, "journal commit ids", -EIO);
+			goto clear_journal;
+		}
+	}
+	DEBUG_print("first unused commit seq %d [%d,%d,%d,%d]\n",
+		    unused, used_commit_ids[0], used_commit_ids[1],
+		    used_commit_ids[2], used_commit_ids[3]);
+
+	last_used = prev_commit_seq(unused);
+	want_commit_seq = prev_commit_seq(last_used);
+
+	if (!used_commit_ids[want_commit_seq] && used_commit_ids[prev_commit_seq(want_commit_seq)])
+		journal_empty = true;
+
+	write_start = max_commit_id_sections[last_used] + 1;
+	if (unlikely(write_start >= ic->journal_sections))
+		want_commit_seq = next_commit_seq(want_commit_seq);
+	wraparound_section(ic, &write_start);
+
+	i = write_start;
+	for (write_sections = 0; write_sections < ic->journal_sections; write_sections++) {
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			struct journal_sector *js = access_journal(ic, i, j);
+
+			if (js->commit_id != dm_integrity_commit_id(ic, i, j, want_commit_seq)) {
+				/*
+				 * This could be caused by crash during writing.
+				 * We won't replay the inconsistent part of the
+				 * journal.
+				 */
+				DEBUG_print("commit id mismatch at position (%u, %u): %d != %d\n",
+					    i, j, find_commit_seq(ic, i, j, js->commit_id), want_commit_seq);
+				goto brk;
+			}
+		}
+		i++;
+		if (unlikely(i >= ic->journal_sections))
+			want_commit_seq = next_commit_seq(want_commit_seq);
+		wraparound_section(ic, &i);
+	}
+brk:
+
+	if (!journal_empty) {
+		DEBUG_print("replaying %u sections, starting at %u, commit seq %d\n",
+			    write_sections, write_start, want_commit_seq);
+		do_journal_write(ic, write_start, write_sections, true);
+	}
+
+	if (write_sections == ic->journal_sections && (ic->mode == 'J' || journal_empty)) {
+		continue_section = write_start;
+		ic->commit_seq = want_commit_seq;
+		DEBUG_print("continuing from section %u, commit seq %d\n", write_start, ic->commit_seq);
+	} else {
+		unsigned s;
+		unsigned char erase_seq;
+clear_journal:
+		DEBUG_print("clearing journal\n");
+
+		erase_seq = prev_commit_seq(prev_commit_seq(last_used));
+		s = write_start;
+		init_journal(ic, s, 1, erase_seq);
+		s++;
+		wraparound_section(ic, &s);
+		if (ic->journal_sections >= 2) {
+			init_journal(ic, s, ic->journal_sections - 2, erase_seq);
+			s += ic->journal_sections - 2;
+			wraparound_section(ic, &s);
+			init_journal(ic, s, 1, erase_seq);
+		}
+
+		continue_section = 0;
+		ic->commit_seq = next_commit_seq(erase_seq);
+	}
+
+	ic->committed_section = continue_section;
+	ic->n_committed_sections = 0;
+
+	ic->uncommitted_section = continue_section;
+	ic->n_uncommitted_sections = 0;
+
+	ic->free_section = continue_section;
+	ic->free_section_entry = 0;
+	ic->free_sectors = ic->journal_entries;
+
+	ic->journal_tree_root = RB_ROOT;
+	for (i = 0; i < ic->journal_entries; i++)
+		init_journal_node(&ic->journal_tree[i]);
+}
+
+static void dm_integrity_postsuspend(struct dm_target *ti)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)ti->private;
+
+	del_timer_sync(&ic->autocommit_timer);
+
+	ic->suspending = true;
+
+	queue_work(ic->commit_wq, &ic->commit_work);
+	drain_workqueue(ic->commit_wq);
+
+	if (ic->mode == 'J') {
+		drain_workqueue(ic->writer_wq);
+		dm_integrity_flush_buffers(ic);
+	}
+
+	ic->suspending = false;
+
+	BUG_ON(!RB_EMPTY_ROOT(&ic->in_progress));
+
+	ic->journal_uptodate = true;
+}
+
+static void dm_integrity_resume(struct dm_target *ti)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)ti->private;
+
+	replay_journal(ic);
+}
+
+static void dm_integrity_status(struct dm_target *ti, status_type_t type,
+				unsigned status_flags, char *result, unsigned maxlen)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)ti->private;
+	unsigned arg_count;
+	size_t sz = 0;
+
+	switch (type) {
+	case STATUSTYPE_INFO:
+		result[0] = '\0';
+		break;
+
+	case STATUSTYPE_TABLE: {
+		__u64 watermark_percentage = (__u64)(ic->journal_entries - ic->free_sectors_threshold) * 100;
+		watermark_percentage += ic->journal_entries / 2;
+		do_div(watermark_percentage, ic->journal_entries);
+		arg_count = 5;
+		arg_count += !!ic->internal_hash_alg.alg_string;
+		arg_count += !!ic->journal_crypt_alg.alg_string;
+		arg_count += !!ic->journal_mac_alg.alg_string;
+		DMEMIT("%s %llu %u %c %u", ic->dev->name, (unsigned long long)ic->start,
+		       ic->tag_size, ic->mode, arg_count);
+		DMEMIT(" journal-sectors:%u", ic->initial_sectors - SB_SECTORS);
+		DMEMIT(" interleave-sectors:%u", 1U << ic->sb->log2_interleave_sectors);
+		DMEMIT(" buffer-sectors:%u", 1U << ic->log2_buffer_sectors);
+		DMEMIT(" journal-watermark:%u", (unsigned)watermark_percentage);
+		DMEMIT(" commit-time:%u", ic->autocommit_msec);
+
+#define EMIT_ALG(a, n)							\
+		do {							\
+			if (ic->a.alg_string) {				\
+				DMEMIT(" %s:%s", n, ic->a.alg_string);	\
+				if (ic->a.key_string)			\
+					DMEMIT(":%s", ic->a.key_string);\
+			}						\
+		} while (0)
+		EMIT_ALG(internal_hash_alg, "internal-hash");
+		EMIT_ALG(journal_crypt_alg, "journal-crypt");
+		EMIT_ALG(journal_mac_alg, "journal-mac");
+		break;
+	}
+	}
+}
+
+static int dm_integrity_iterate_devices(struct dm_target *ti,
+					iterate_devices_callout_fn fn, void *data)
+{
+	struct dm_integrity_c *ic = ti->private;
+
+	return fn(ti, ic->dev, ic->start + ic->initial_sectors + ic->metadata_run, ti->len, data);
+}
+
+static void calculate_journal_section_size(struct dm_integrity_c *ic)
+{
+	unsigned sector_space = JOURNAL_SECTOR_DATA;
+
+	ic->journal_sections = le32_to_cpu(ic->sb->journal_sections);
+	ic->journal_entry_size = roundup(offsetof(struct journal_entry, tag) + ic->tag_size,
+					 JOURNAL_ENTRY_ROUNDUP);
+
+	if (ic->sb->flags & cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC))
+		sector_space -= JOURNAL_MAC_PER_SECTOR;
+	ic->journal_entries_per_sector = sector_space / ic->journal_entry_size;
+	ic->journal_section_entries = ic->journal_entries_per_sector * JOURNAL_BLOCK_SECTORS;
+	ic->journal_section_sectors = ic->journal_section_entries + JOURNAL_BLOCK_SECTORS;
+	ic->journal_entries = ic->journal_section_entries * ic->journal_sections;
+}
+
+static int calculate_device_limits(struct dm_integrity_c *ic)
+{
+	__u64 initial_sectors;
+	sector_t last_sector, last_area, last_offset;
+
+	calculate_journal_section_size(ic);
+	initial_sectors = SB_SECTORS + (__u64)ic->journal_section_sectors * ic->journal_sections;
+	if (initial_sectors + METADATA_PADDING_SECTORS >= ic->device_sectors || initial_sectors > UINT_MAX)
+		return -EINVAL;
+	ic->initial_sectors = initial_sectors;
+
+	ic->metadata_run = roundup((__u64)ic->tag_size << ic->sb->log2_interleave_sectors,
+				   (__u64)(1 << SECTOR_SHIFT << METADATA_PADDING_SECTORS)) >> SECTOR_SHIFT;
+	if (!(ic->metadata_run & (ic->metadata_run - 1)))
+		ic->log2_metadata_run = __ffs(ic->metadata_run);
+	else
+		ic->log2_metadata_run = -1;
+
+	get_area_and_offset(ic, ic->provided_data_sectors - 1, &last_area, &last_offset);
+	last_sector = get_data_sector(ic, last_area, last_offset);
+
+	if (ic->start + last_sector < last_sector || ic->start + last_sector >= ic->device_sectors)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sectors, unsigned interleave_sectors)
+{
+	unsigned journal_sections;
+	int test_bit;
+
+	memcpy(ic->sb->magic, SB_MAGIC, 8);
+	ic->sb->version = SB_VERSION;
+	ic->sb->integrity_tag_size = cpu_to_le16(ic->tag_size);
+	if (ic->journal_mac_alg.alg_string)
+		ic->sb->flags |= cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC);
+
+	calculate_journal_section_size(ic);
+	journal_sections = journal_sectors / ic->journal_section_sectors;
+	if (!journal_sections)
+		journal_sections = 1;
+	ic->sb->journal_sections = cpu_to_le32(journal_sections);
+
+	ic->sb->log2_interleave_sectors = __fls(interleave_sectors);
+	ic->sb->log2_interleave_sectors = max((__u8)MIN_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
+	ic->sb->log2_interleave_sectors = min((__u8)MAX_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
+
+	ic->provided_data_sectors = 0;
+	for (test_bit = fls64(ic->device_sectors) - 1; test_bit >= 3; test_bit--) {
+		__u64 prev_data_sectors = ic->provided_data_sectors;
+
+		ic->provided_data_sectors |= (sector_t)1 << test_bit;
+		if (calculate_device_limits(ic))
+			ic->provided_data_sectors = prev_data_sectors;
+	}
+
+	if (!le64_to_cpu(ic->provided_data_sectors))
+		return -EINVAL;
+
+	ic->sb->provided_data_sectors = cpu_to_le64(ic->provided_data_sectors);
+
+	return 0;
+}
+
+static void dm_integrity_set(struct dm_target *ti, struct dm_integrity_c *ic)
+{
+	struct gendisk *disk = dm_disk(dm_table_get_md(ti->table));
+	struct blk_integrity bi;
+
+	memset(&bi, 0, sizeof(bi));
+	bi.profile = &dm_integrity_profile;
+	bi.tuple_size = ic->tag_size * (queue_logical_block_size(disk->queue) >> SECTOR_SHIFT);
+	bi.tag_size = ic->tag_size;
+
+	blk_integrity_register(disk, &bi);
+	blk_queue_max_integrity_segments(disk->queue, UINT_MAX);
+}
+
+/* FIXME: use new kvmalloc */
+static void *dm_integrity_kvmalloc(size_t size, gfp_t gfp)
+{
+	void *ptr = NULL;
+
+	if (size <= PAGE_SIZE)
+		ptr = kmalloc(size, GFP_KERNEL | gfp);
+	if (!ptr && size <= KMALLOC_MAX_SIZE)
+		ptr = kmalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | gfp);
+	if (!ptr)
+		ptr = __vmalloc(size, GFP_KERNEL | gfp, PAGE_KERNEL);
+
+	return ptr;
+}
+
+static void dm_integrity_free_page_list(struct dm_integrity_c *ic, struct page_list *pl)
+{
+	unsigned i;
+
+	if (!pl)
+		return;
+	for (i = 0; i < ic->journal_pages; i++)
+		if (pl[i].page)
+			__free_page(pl[i].page);
+	kvfree(pl);
+}
+
+static struct page_list *dm_integrity_alloc_page_list(struct dm_integrity_c *ic)
+{
+	size_t page_list_desc_size = ic->journal_pages * sizeof(struct page_list);
+	struct page_list *pl;
+	unsigned i;
+
+	pl = dm_integrity_kvmalloc(page_list_desc_size, __GFP_ZERO);
+	if (!pl)
+		return NULL;
+
+	for (i = 0; i < ic->journal_pages; i++) {
+		pl[i].page = alloc_page(GFP_KERNEL);
+		if (!pl[i].page) {
+			dm_integrity_free_page_list(ic, pl);
+			return NULL;
+		}
+		if (i)
+			pl[i - 1].next = &pl[i];
+	}
+
+	return pl;
+}
+
+static void dm_integrity_free_journal_scatterlist(struct dm_integrity_c *ic, struct scatterlist **sl)
+{
+	unsigned i;
+	for (i = 0; i < ic->journal_sections; i++)
+		kvfree(sl[i]);
+	kfree(sl);
+}
+
+static struct scatterlist **dm_integrity_alloc_journal_scatterlist(struct dm_integrity_c *ic, struct page_list *pl)
+{
+	struct scatterlist **sl;
+	unsigned i;
+
+	sl = dm_integrity_kvmalloc(ic->journal_sections * sizeof(struct scatterlist *), __GFP_ZERO);
+	if (!sl)
+		return NULL;
+
+	for (i = 0; i < ic->journal_sections; i++) {
+		struct scatterlist *s;
+		unsigned start_index, start_offset;
+		unsigned end_index, end_offset;
+		unsigned n_pages;
+		unsigned idx;
+
+		page_list_location(ic, i, 0, &start_index, &start_offset);
+		page_list_location(ic, i, ic->journal_section_sectors - 1, &end_index, &end_offset);
+
+		n_pages = (end_index - start_index + 1);
+
+		s = dm_integrity_kvmalloc(n_pages * sizeof(struct scatterlist), 0);
+		if (!s) {
+			dm_integrity_free_journal_scatterlist(ic, sl);
+			return NULL;
+		}
+
+		sg_init_table(s, n_pages);
+		for (idx = start_index; idx <= end_index; idx++) {
+			char *va = lowmem_page_address(pl[idx].page);
+			unsigned start = 0, end = PAGE_SIZE;
+			if (idx == start_index)
+				start = start_offset;
+			if (idx == end_index)
+				end = end_offset + (1 << SECTOR_SHIFT);
+			sg_set_buf(&s[idx - start_index], va + start, end - start);
+		}
+
+		sl[i] = s;
+	}
+
+	return sl;
+}
+
+static void free_alg(struct alg_spec *a)
+{
+	kzfree(a->alg_string);
+	kzfree(a->key);
+	memset(a, 0, sizeof *a);
+}
+
+static int get_alg_and_key(const char *arg, struct alg_spec *a, char **error, char *error_inval)
+{
+	char *k;
+
+	free_alg(a);
+
+	a->alg_string = kstrdup(strchr(arg, ':') + 1, GFP_KERNEL);
+	if (!a->alg_string)
+		goto nomem;
+
+	k = strchr(a->alg_string, ':');
+	if (k) {
+		unsigned i;
+
+		*k = 0;
+		a->key_string = k + 1;
+		if (strlen(a->key_string) & 1)
+			goto inval;
+
+		a->key_size = strlen(a->key_string) / 2;
+		a->key = kmalloc(a->key_size, GFP_KERNEL);
+		if (!a->key)
+			goto nomem;
+		for (i = 0; i < a->key_size; i++) {
+			char digit[3];
+			digit[0] = a->key_string[i * 2];
+			digit[1] = a->key_string[i * 2 + 1];
+			digit[2] = 0;
+			if (strspn(digit, "0123456789abcdefABCDEF") != 2)
+				goto inval;
+			if (kstrtou8(digit, 16, &a->key[i]))
+				goto inval;
+		}
+	}
+
+	return 0;
+inval:
+	*error = error_inval;
+	return -EINVAL;
+nomem:
+	*error = "Out of memory for an argument";
+	return -ENOMEM;
+}
+
+static int get_mac(struct crypto_shash **hash, struct alg_spec *a, char **error,
+		   char *error_alg, char *error_key)
+{
+	int r;
+
+	if (a->alg_string) {
+		*hash = crypto_alloc_shash(a->alg_string, 0, CRYPTO_ALG_ASYNC);
+		if (IS_ERR(*hash)) {
+			*error = error_alg;
+			r = PTR_ERR(*hash);
+			*hash = NULL;
+			return r;
+		}
+
+		if (a->key) {
+			r = crypto_shash_setkey(*hash, a->key, a->key_size);
+			if (r) {
+				*error = error_key;
+				return r;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Construct a integrity mapping: <dev_path> <offset> <tag_size>
+ *
+ * Arguments:
+ *	device
+ *	offset from the start of the device
+ *	tag size
+ *	D - direct writes, J - journal writes
+ *	number of optional arguments
+ *	optional arguments:
+ *		journal-sectors
+ *		interleave-sectors
+ *		buffer-sectors
+ *		journal-watermark
+ *		commit-time
+ *		internal-hash
+ *		journal-crypt
+ *		journal-mac
+ */
+static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
+{
+	struct dm_integrity_c *ic;
+	char dummy;
+	int r;
+	unsigned i;
+	unsigned extra_args;
+	struct dm_arg_set as;
+	static struct dm_arg _args[] = {
+		{0, 7, "Invalid number of feature args"},
+	};
+	unsigned journal_sectors, interleave_sectors, buffer_sectors, journal_watermark, sync_msec;
+	bool should_write_sb;
+	__u64 journal_pages, journal_desc_size, journal_tree_size;
+	__u64 threshold;
+	unsigned long long start;
+
+#define DIRECT_ARGUMENTS	4
+
+	if (argc <= DIRECT_ARGUMENTS) {
+		ti->error = "Invalid argument count";
+		return -EINVAL;
+	}
+
+	ic = kzalloc(sizeof(struct dm_integrity_c), GFP_KERNEL);
+	if (!ic) {
+		ti->error = "Cannot allocate integrity context";
+		return -ENOMEM;
+	}
+	ti->private = ic;
+	ti->per_io_data_size = sizeof(struct dm_integrity_io);
+
+	ic->commit_ids[0] = cpu_to_le64(0x1111111111111111ULL);
+	ic->commit_ids[1] = cpu_to_le64(0x2222222222222222ULL);
+	ic->commit_ids[2] = cpu_to_le64(0x3333333333333333ULL);
+	ic->commit_ids[3] = cpu_to_le64(0x4444444444444444ULL);
+
+	ic->in_progress = RB_ROOT;
+	init_waitqueue_head(&ic->endio_wait);
+	bio_list_init(&ic->flush_bio_list);
+	init_waitqueue_head(&ic->copy_to_journal_wait);
+	init_completion(&ic->crypto_backoff);
+
+	r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &ic->dev);
+	if (r) {
+		ti->error = "Device lookup failed";
+		goto bad;
+	}
+
+	if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) {
+		ti->error = "Invalid starting offset";
+		r = -EINVAL;
+		goto bad;
+	}
+	ic->start = start;
+
+	if (strcmp(argv[2], "-")) {
+		if (sscanf(argv[2], "%u%c", &ic->tag_size, &dummy) != 1 || !ic->tag_size) {
+			ti->error = "Invalid tag size";
+			r = -EINVAL;
+			goto bad;
+		}
+	}
+
+	if (!strcmp(argv[3], "J") || !strcmp(argv[3], "D"))
+		ic->mode = argv[3][0];
+	else {
+		ti->error = "Invalid mode (expecting J or D)";
+		r = -EINVAL;
+		goto bad;
+	}
+
+	ic->device_sectors = i_size_read(ic->dev->bdev->bd_inode) >> SECTOR_SHIFT;
+	journal_sectors = min((sector_t)DEFAULT_MAX_JOURNAL_SECTORS,
+			ic->device_sectors >> DEFAULT_JOURNAL_SIZE_FACTOR);
+	interleave_sectors = DEFAULT_INTERLEAVE_SECTORS;
+	buffer_sectors = DEFAULT_BUFFER_SECTORS;
+	journal_watermark = DEFAULT_JOURNAL_WATERMARK;
+	sync_msec = DEFAULT_SYNC_MSEC;
+
+	as.argc = argc - DIRECT_ARGUMENTS;
+	as.argv = argv + DIRECT_ARGUMENTS;
+	r = dm_read_arg_group(_args, &as, &extra_args, &ti->error);
+	if (r)
+		goto bad;
+
+	while (extra_args--) {
+		const char *opt_string;
+		unsigned val;
+		opt_string = dm_shift_arg(&as);
+		if (!opt_string) {
+			r = -EINVAL;
+			ti->error = "Not enough feature arguments";
+			goto bad;
+		}
+		if (sscanf(opt_string, "journal-sectors:%u%c", &val, &dummy) == 1)
+			journal_sectors = val;
+		else if (sscanf(opt_string, "interleave-sectors:%u%c", &val, &dummy) == 1)
+			interleave_sectors = val;
+		else if (sscanf(opt_string, "buffer-sectors:%u%c", &val, &dummy) == 1)
+			buffer_sectors = val;
+		else if (sscanf(opt_string, "journal-watermark:%u%c", &val, &dummy) == 1 && val <= 100)
+			journal_watermark = val;
+		else if (sscanf(opt_string, "commit-time:%u%c", &val, &dummy) == 1)
+			sync_msec = val;
+		else if (!memcmp(opt_string, "internal-hash:", strlen("internal-hash:"))) {
+			r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
+					    "Invalid internal-hash argument");
+			if (r)
+				goto bad;
+		} else if (!memcmp(opt_string, "journal-crypt:", strlen("journal-crypt:"))) {
+			r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
+					    "Invalid journal-crypt argument");
+			if (r)
+				goto bad;
+		} else if (!memcmp(opt_string, "journal-mac:", strlen("journal-mac:"))) {
+			r = get_alg_and_key(opt_string, &ic->journal_mac_alg,  &ti->error,
+					    "Invalid journal-mac argument");
+			if (r)
+				goto bad;
+		} else {
+			r = -EINVAL;
+			ti->error = "Invalid argument";
+			goto bad;
+		}
+	}
+
+	r = get_mac(&ic->internal_hash, &ic->internal_hash_alg, &ti->error,
+		    "Invalid internal hash", "Error setting internal hash key");
+	if (r)
+		goto bad;
+
+	r = get_mac(&ic->journal_mac, &ic->journal_mac_alg, &ti->error,
+		    "Invalid journal mac", "Error setting journal mac key");
+	if (r)
+		goto bad;
+
+	if (!ic->tag_size) {
+		if (!ic->internal_hash) {
+			ti->error = "Unknown tag size";
+			r = -EINVAL;
+			goto bad;
+		}
+		ic->tag_size = crypto_shash_digestsize(ic->internal_hash);
+	}
+	if (ic->tag_size > MAX_TAG_SIZE) {
+		ti->error = "Too big tag size";
+		r = -EINVAL;
+		goto bad;
+	}
+	if (!(ic->tag_size & (ic->tag_size - 1)))
+		ic->log2_tag_size = __ffs(ic->tag_size);
+	else
+		ic->log2_tag_size = -1;
+
+	ic->autocommit_jiffies = msecs_to_jiffies(sync_msec);
+	ic->autocommit_msec = sync_msec;
+	setup_timer(&ic->autocommit_timer, autocommit_fn, (unsigned long)ic);
+
+	ic->io = dm_io_client_create();
+	if (IS_ERR(ic->io)) {
+		r = PTR_ERR(ic->io);
+		ic->io = NULL;
+		ti->error = "Cannot allocate dm io";
+		goto bad;
+	}
+
+	ic->journal_io_mempool = mempool_create_slab_pool(JOURNAL_IO_MEMPOOL, journal_io_cache);
+	if (!ic->journal_io_mempool) {
+		r = -ENOMEM;
+		ti->error = "Cannot allocate mempool";
+		goto bad;
+	}
+
+	ic->metadata_wq = alloc_workqueue("dm-integrity-metadata",
+					  WQ_MEM_RECLAIM, METADATA_WORKQUEUE_MAX_ACTIVE);
+	if (!ic->metadata_wq) {
+		ti->error = "Cannot allocate workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+
+	/*
+	 * If this workqueue were percpu, it would cause bio reordering
+	 * and reduced performance.
+	 */
+	ic->wait_wq = alloc_workqueue("dm-integrity-wait", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
+	if (!ic->wait_wq) {
+		ti->error = "Cannot allocate workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+
+	ic->commit_wq = alloc_workqueue("dm-integrity-commit", WQ_MEM_RECLAIM, 1);
+	if (!ic->commit_wq) {
+		ti->error = "Cannot allocate workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+	INIT_WORK(&ic->commit_work, integrity_commit);
+
+	if (ic->mode == 'J') {
+		ic->writer_wq = alloc_workqueue("dm-integrity-writer", WQ_MEM_RECLAIM, 1);
+		if (!ic->writer_wq) {
+			ti->error = "Cannot allocate workqueue";
+			r = -ENOMEM;
+			goto bad;
+		}
+		INIT_WORK(&ic->writer_work, integrity_writer);
+	}
+
+	ic->sb = alloc_pages_exact(SB_SECTORS << SECTOR_SHIFT, GFP_KERNEL);
+	if (!ic->sb) {
+		r = -ENOMEM;
+		ti->error = "Cannot allocate superblock area";
+		goto bad;
+	}
+
+	r = sync_rw_sb(ic, REQ_OP_READ, 0);
+	if (r) {
+		ti->error = "Error reading superblock";
+		goto bad;
+	}
+	if (!memcmp(ic->sb->magic, SB_MAGIC, 8)) {
+		should_write_sb = false;
+	} else {
+		for (i = 0; i < 512; i += 8) {
+			if (*(__u64 *)((__u8 *)ic->sb + i)) {
+				r = -EINVAL;
+				ti->error = "The device is not initialized";
+				goto bad;
+			}
+		}
+
+		r = initialize_superblock(ic, journal_sectors, interleave_sectors);
+		if (r) {
+			ti->error = "Could not initialize superblock";
+			goto bad;
+		}
+		should_write_sb = true;
+	}
+
+	if (ic->sb->version != SB_VERSION) {
+		r = -EINVAL;
+		ti->error = "Unknown version";
+		goto bad;
+	}
+	if (le16_to_cpu(ic->sb->integrity_tag_size) != ic->tag_size) {
+		r = -EINVAL;
+		ti->error = "Invalid tag size";
+		goto bad;
+	}
+	/* make sure that ti->max_io_len doesn't overflow */
+	if (ic->sb->log2_interleave_sectors < MIN_INTERLEAVE_SECTORS ||
+	    ic->sb->log2_interleave_sectors > MAX_INTERLEAVE_SECTORS) {
+		r = -EINVAL;
+		ti->error = "Invalid interleave_sectors in the superblock";
+		goto bad;
+	}
+	ic->provided_data_sectors = le64_to_cpu(ic->sb->provided_data_sectors);
+	if (ic->provided_data_sectors != le64_to_cpu(ic->sb->provided_data_sectors)) {
+		/* test for overflow */
+		r = -EINVAL;
+		ti->error = "The superblock has 64-bit device size, but the kernel was compiled with 32-bit sectors";
+		goto bad;
+	}
+	if (!!(ic->sb->flags & cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC)) != !!ic->journal_mac_alg.alg_string) {
+		r = -EINVAL;
+		ti->error = "Journal mac mismatch";
+		goto bad;
+	}
+	r = calculate_device_limits(ic);
+	if (r) {
+		ti->error = "The device is too small";
+		goto bad;
+	}
+
+	if (!buffer_sectors)
+		buffer_sectors = 1;
+	ic->log2_buffer_sectors = min3((int)__fls(buffer_sectors), (int)__ffs(ic->metadata_run), 31 - SECTOR_SHIFT);
+
+	threshold = (__u64)ic->journal_entries * (100 - journal_watermark);
+	threshold += 50;
+	do_div(threshold, 100);
+	ic->free_sectors_threshold = threshold;
+
+	DEBUG_print("initialized:\n");
+	DEBUG_print("	integrity_tag_size %u\n", le16_to_cpu(ic->sb->integrity_tag_size));
+	DEBUG_print("	journal_entry_size %u\n", ic->journal_entry_size);
+	DEBUG_print("	journal_entries_per_sector %u\n", ic->journal_entries_per_sector);
+	DEBUG_print("	journal_section_entries %u\n", ic->journal_section_entries);
+	DEBUG_print("	journal_section_sectors %u\n", ic->journal_section_sectors);
+	DEBUG_print("	journal_sections %u\n", (unsigned)le32_to_cpu(ic->sb->journal_sections));
+	DEBUG_print("	journal_entries %u\n", ic->journal_entries);
+	DEBUG_print("	log2_interleave_sectors %d\n", ic->sb->log2_interleave_sectors);
+	DEBUG_print("	device_sectors 0x%llx\n", (unsigned long long)ic->device_sectors);
+	DEBUG_print("	initial_sectors 0x%x\n", ic->initial_sectors);
+	DEBUG_print("	metadata_run 0x%x\n", ic->metadata_run);
+	DEBUG_print("	log2_metadata_run %d\n", ic->log2_metadata_run);
+	DEBUG_print("	provided_data_sectors 0x%llx (%llu)\n", (unsigned long long)ic->provided_data_sectors,
+		    (unsigned long long)ic->provided_data_sectors);
+	DEBUG_print("	log2_buffer_sectors %u\n", ic->log2_buffer_sectors);
+
+	ic->bufio = dm_bufio_client_create(ic->dev->bdev, 1U << (SECTOR_SHIFT + ic->log2_buffer_sectors),
+					   1, 0, NULL, NULL);
+	if (IS_ERR(ic->bufio)) {
+		r = PTR_ERR(ic->bufio);
+		ti->error = "Cannot initialize dm-bufio";
+		ic->bufio = NULL;
+		goto bad;
+	}
+	dm_bufio_set_sector_offset(ic->bufio, ic->start + ic->initial_sectors);
+
+	journal_pages = roundup((__u64)ic->journal_sections * ic->journal_section_sectors,
+				PAGE_SIZE >> SECTOR_SHIFT) >> (PAGE_SHIFT - SECTOR_SHIFT);
+	journal_desc_size = journal_pages * sizeof(struct page_list);
+	if (journal_pages >= totalram_pages - totalhigh_pages || journal_desc_size > ULONG_MAX) {
+		ti->error = "Journal doesn't fit into memory";
+		r = -ENOMEM;
+		goto bad;
+	}
+	ic->journal_pages = journal_pages;
+
+	ic->journal = dm_integrity_alloc_page_list(ic);
+	if (!ic->journal) {
+		ti->error = "Could not allocate memory for journal";
+		r = -ENOMEM;
+		goto bad;
+	}
+	if (ic->journal_crypt_alg.alg_string) {
+		unsigned ivsize, blocksize;
+		struct journal_completion comp;
+		comp.ic = ic;
+
+		ic->journal_crypt = crypto_alloc_skcipher(ic->journal_crypt_alg.alg_string, 0, 0);
+		if (IS_ERR(ic->journal_crypt)) {
+			ti->error = "Invalid journal cipher";
+			r = PTR_ERR(ic->journal_crypt);
+			ic->journal_crypt = NULL;
+			goto bad;
+		}
+		ivsize = crypto_skcipher_ivsize(ic->journal_crypt);
+		blocksize = crypto_skcipher_blocksize(ic->journal_crypt);
+
+		if (ic->journal_crypt_alg.key) {
+			r = crypto_skcipher_setkey(ic->journal_crypt, ic->journal_crypt_alg.key,
+						   ic->journal_crypt_alg.key_size);
+			if (r) {
+				ti->error = "Error setting encryption key";
+				goto bad;
+			}
+		}
+		DEBUG_print("cipher %s, block size %u iv size %u\n",
+			    ic->journal_crypt_alg.alg_string, blocksize, ivsize);
+
+		ic->journal_io = dm_integrity_alloc_page_list(ic);
+		if (!ic->journal_io) {
+			ti->error = "Could not allocate memory for journal io";
+			r = -ENOMEM;
+			goto bad;
+		}
+
+		if (blocksize == 1) {
+			struct scatterlist *sg;
+			SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt);
+			unsigned char iv[ivsize];
+			skcipher_request_set_tfm(req, ic->journal_crypt);
+
+			ic->journal_xor = dm_integrity_alloc_page_list(ic);
+			if (!ic->journal_xor) {
+				ti->error = "Could not allocate memory for journal xor";
+				r = -ENOMEM;
+				goto bad;
+			}
+
+			sg = dm_integrity_kvmalloc((ic->journal_pages + 1) * sizeof(struct scatterlist), 0);
+			if (!sg) {
+				ti->error = "Unable to allocate sg list";
+				r = -ENOMEM;
+				goto bad;
+			}
+			sg_init_table(sg, ic->journal_pages + 1);
+			for (i = 0; i < ic->journal_pages; i++) {
+				char *va = lowmem_page_address(ic->journal_xor[i].page);
+				clear_page(va);
+				sg_set_buf(&sg[i], va, PAGE_SIZE);
+			}
+			sg_set_buf(&sg[i], &ic->commit_ids, sizeof ic->commit_ids);
+			memset(iv, 0x00, ivsize);
+
+			skcipher_request_set_crypt(req, sg, sg, PAGE_SIZE * ic->journal_pages + sizeof ic->commit_ids, iv);
+			comp.comp = COMPLETION_INITIALIZER_ONSTACK(comp.comp);
+			comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+			if (do_crypt(true, req, &comp))
+				wait_for_completion(&comp.comp);
+			kvfree(sg);
+			if ((r = dm_integrity_failed(ic))) {
+				ti->error = "Unable to encrypt journal";
+				goto bad;
+			}
+			DEBUG_bytes(lowmem_page_address(ic->journal_xor[0].page), 64, "xor data");
+
+			crypto_free_skcipher(ic->journal_crypt);
+			ic->journal_crypt = NULL;
+		} else {
+			SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt);
+			unsigned char iv[ivsize];
+			unsigned crypt_len = roundup(ivsize, blocksize);
+			unsigned char crypt_data[crypt_len];
+
+			skcipher_request_set_tfm(req, ic->journal_crypt);
+
+			ic->journal_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal);
+			if (!ic->journal_scatterlist) {
+				ti->error = "Unable to allocate sg list";
+				r = -ENOMEM;
+				goto bad;
+			}
+			ic->journal_io_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal_io);
+			if (!ic->journal_io_scatterlist) {
+				ti->error = "Unable to allocate sg list";
+				r = -ENOMEM;
+				goto bad;
+			}
+			ic->sk_requests = dm_integrity_kvmalloc(ic->journal_sections * sizeof(struct skcipher_request *), __GFP_ZERO);
+			if (!ic->sk_requests) {
+				ti->error = "Unable to allocate sk requests";
+				r = -ENOMEM;
+				goto bad;
+			}
+			for (i = 0; i < ic->journal_sections; i++) {
+				struct scatterlist sg;
+				struct skcipher_request *section_req;
+				__u32 section_le = cpu_to_le32(i);
+
+				memset(iv, 0x00, ivsize);
+				memset(crypt_data, 0x00, crypt_len);
+				memcpy(crypt_data, &section_le, min((size_t)crypt_len, sizeof(section_le)));
+
+				sg_init_one(&sg, crypt_data, crypt_len);
+				skcipher_request_set_crypt(req, &sg, &sg, crypt_len, iv);
+				comp.comp = COMPLETION_INITIALIZER_ONSTACK(comp.comp);
+				comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+				if (do_crypt(true, req, &comp))
+					wait_for_completion(&comp.comp);
+
+				if ((r = dm_integrity_failed(ic))) {
+					ti->error = "Unable to generate iv";
+					goto bad;
+				}
+
+				section_req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL);
+				if (!section_req) {
+					ti->error = "Unable to allocate crypt request";
+					r = -ENOMEM;
+					goto bad;
+				}
+				section_req->iv = kmalloc(ivsize * 2, GFP_KERNEL);
+				if (!section_req->iv) {
+					skcipher_request_free(section_req);
+					ti->error = "Unable to allocate iv";
+					r = -ENOMEM;
+					goto bad;
+				}
+				memcpy(section_req->iv + ivsize, crypt_data, ivsize);
+				section_req->cryptlen = (size_t)ic->journal_section_sectors << SECTOR_SHIFT;
+				ic->sk_requests[i] = section_req;
+				DEBUG_bytes(crypt_data, ivsize, "iv(%u)", i);
+			}
+		}
+	}
+
+	for (i = 0; i < N_COMMIT_IDS; i++) {
+		unsigned j;
+retest_commit_id:
+		for (j = 0; j < i; j++) {
+			if (ic->commit_ids[j] == ic->commit_ids[i]) {
+				ic->commit_ids[i] = cpu_to_le64(le64_to_cpu(ic->commit_ids[i]) + 1);
+				goto retest_commit_id;
+			}
+		}
+		DEBUG_print("commit id %u: %016llx\n", i, ic->commit_ids[i]);
+	}
+
+	journal_tree_size = (__u64)ic->journal_entries * sizeof(struct journal_node);
+	if (journal_tree_size > ULONG_MAX) {
+		ti->error = "Journal doesn't fit into memory";
+		r = -ENOMEM;
+		goto bad;
+	}
+	ic->journal_tree = dm_integrity_kvmalloc(journal_tree_size, 0);
+	if (!ic->journal_tree) {
+		ti->error = "Could not allocate memory for journal tree";
+		r = -ENOMEM;
+		goto bad;
+	}
+
+	if (should_write_sb) {
+		int r;
+
+		init_journal(ic, 0, ic->journal_sections, 0);
+		r = dm_integrity_failed(ic);
+		if (unlikely(r)) {
+			ti->error = "Error initializing journal";
+			goto bad;
+		}
+		r = sync_rw_sb(ic, REQ_OP_WRITE, REQ_FUA);
+		if (r) {
+			ti->error = "Error initializing superblock";
+			goto bad;
+		}
+		ic->just_formatted = true;
+	}
+
+	r = dm_set_target_max_io_len(ti, 1U << ic->sb->log2_interleave_sectors);
+	if (r)
+		goto bad;
+
+	if (!ic->internal_hash)
+		dm_integrity_set(ti, ic);
+
+	ti->num_flush_bios = 1;
+	ti->flush_supported = true;
+
+	return 0;
+bad:
+	dm_integrity_dtr(ti);
+	return r;
+}
+
+static void dm_integrity_dtr(struct dm_target *ti)
+{
+	struct dm_integrity_c *ic = ti->private;
+
+	BUG_ON(!RB_EMPTY_ROOT(&ic->in_progress));
+
+	if (ic->metadata_wq)
+		destroy_workqueue(ic->metadata_wq);
+	if (ic->wait_wq)
+		destroy_workqueue(ic->wait_wq);
+	if (ic->commit_wq)
+		destroy_workqueue(ic->commit_wq);
+	if (ic->writer_wq)
+		destroy_workqueue(ic->writer_wq);
+	if (ic->bufio)
+		dm_bufio_client_destroy(ic->bufio);
+	mempool_destroy(ic->journal_io_mempool);
+	if (ic->io)
+		dm_io_client_destroy(ic->io);
+	if (ic->dev)
+		dm_put_device(ti, ic->dev);
+	dm_integrity_free_page_list(ic, ic->journal);
+	dm_integrity_free_page_list(ic, ic->journal_io);
+	dm_integrity_free_page_list(ic, ic->journal_xor);
+	if (ic->journal_scatterlist)
+		dm_integrity_free_journal_scatterlist(ic, ic->journal_scatterlist);
+	if (ic->journal_io_scatterlist)
+		dm_integrity_free_journal_scatterlist(ic, ic->journal_io_scatterlist);
+	if (ic->sk_requests) {
+		unsigned i;
+
+		for (i = 0; i < ic->journal_sections; i++) {
+			struct skcipher_request *req = ic->sk_requests[i];
+			if (req) {
+				kzfree(req->iv);
+				skcipher_request_free(req);
+			}
+		}
+		kvfree(ic->sk_requests);
+	}
+	kvfree(ic->journal_tree);
+	if (ic->sb)
+		free_pages_exact(ic->sb, SB_SECTORS << SECTOR_SHIFT);
+
+	if (ic->internal_hash)
+		crypto_free_shash(ic->internal_hash);
+	free_alg(&ic->internal_hash_alg);
+
+	if (ic->journal_crypt)
+		crypto_free_skcipher(ic->journal_crypt);
+	free_alg(&ic->journal_crypt_alg);
+
+	if (ic->journal_mac)
+		crypto_free_shash(ic->journal_mac);
+	free_alg(&ic->journal_mac_alg);
+
+	kfree(ic);
+}
+
+static struct target_type integrity_target = {
+	.name			= "integrity",
+	.version		= {1, 0, 0},
+	.module			= THIS_MODULE,
+	.features		= DM_TARGET_SINGLETON | DM_TARGET_INTEGRITY,
+	.ctr			= dm_integrity_ctr,
+	.dtr			= dm_integrity_dtr,
+	.map			= dm_integrity_map,
+	.postsuspend		= dm_integrity_postsuspend,
+	.resume			= dm_integrity_resume,
+	.status			= dm_integrity_status,
+	.iterate_devices	= dm_integrity_iterate_devices,
+};
+
+int __init dm_integrity_init(void)
+{
+	int r;
+
+	journal_io_cache = kmem_cache_create("integrity_journal_io",
+					     sizeof(struct journal_io), 0, 0, NULL);
+	if (!journal_io_cache) {
+		DMERR("can't allocate journal io cache");
+		return -ENOMEM;
+	}
+
+	r = dm_register_target(&integrity_target);
+
+	if (r < 0)
+		DMERR("register failed %d", r);
+
+	return r;
+}
+
+void dm_integrity_exit(void)
+{
+	dm_unregister_target(&integrity_target);
+	kmem_cache_destroy(journal_io_cache);
+}
+
+module_init(dm_integrity_init);
+module_exit(dm_integrity_exit);
+
+MODULE_AUTHOR("Milan Broz");
+MODULE_AUTHOR("Mikulas Patocka");
+MODULE_DESCRIPTION(DM_NAME " target for integrity tags extension");
+MODULE_LICENSE("GPL");